U.S. patent application number 13/058546 was filed with the patent office on 2011-06-16 for wireless terminal positioning system, method of positioning wireless terminal, environment measurment system, facility management system, method of measuring environment, and method of deciding destination of wireless mobile terminal.
This patent application is currently assigned to Mitsubishi Electric Corporation. Invention is credited to Naoyuki Hibara, Yoshiaki Koizumi, Noriyuki Kushiro, Masanori Nakata.
Application Number | 20110141909 13/058546 |
Document ID | / |
Family ID | 41707053 |
Filed Date | 2011-06-16 |
United States Patent
Application |
20110141909 |
Kind Code |
A1 |
Hibara; Naoyuki ; et
al. |
June 16, 2011 |
WIRELESS TERMINAL POSITIONING SYSTEM, METHOD OF POSITIONING
WIRELESS TERMINAL, ENVIRONMENT MEASURMENT SYSTEM, FACILITY
MANAGEMENT SYSTEM, METHOD OF MEASURING ENVIRONMENT, AND METHOD OF
DECIDING DESTINATION OF WIRELESS MOBILE TERMINAL
Abstract
To obtain a method of positioning a wireless terminal capable of
obtaining the position of each communication terminal by measuring
distances with installed communication terminals each other without
fixedly installing a base station. A positioning management
terminal 100 includes a positioning object decision section 130
that selects a terminal to be positioned, which is a positioning
object, and a positioning standard terminal, whose position is
known, among the wireless terminals 200; a positioning management
section 120 that requires distance information between the terminal
to be positioned and the positioning standard terminal; and a
position calculation section 140 that calculates the position of
the terminal to be positioned. The positioning management section
120 requires distance information from the positioning standard
terminal selected by the positioning object decision section 130 to
the terminal to be positioned selected by the positioning object
decision section 130. The position calculation section 140
calculates the position of the terminal to be positioned using the
distance information and position information of the positioning
standard terminal.
Inventors: |
Hibara; Naoyuki; (Tokyo,
JP) ; Koizumi; Yoshiaki; (Tokyo, JP) ; Nakata;
Masanori; (Tokyo, JP) ; Kushiro; Noriyuki;
(Tokyo, JP) |
Assignee: |
Mitsubishi Electric
Corporation
Chiyoda-ku, Tokyo
JP
|
Family ID: |
41707053 |
Appl. No.: |
13/058546 |
Filed: |
March 13, 2009 |
PCT Filed: |
March 13, 2009 |
PCT NO: |
PCT/JP2009/054900 |
371 Date: |
February 11, 2011 |
Current U.S.
Class: |
370/241 |
Current CPC
Class: |
G01S 5/021 20130101;
H04W 64/00 20130101; H04W 84/18 20130101; G01S 5/0289 20130101;
G01S 5/0036 20130101; G01S 5/14 20130101 |
Class at
Publication: |
370/241 |
International
Class: |
H04L 12/26 20060101
H04L012/26 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 20, 2008 |
JP |
2008-211454 |
Claims
1. A wireless terminal positioning system including one or a
plurality of wireless terminals and a positioning management
terminal that manages positioning of said wireless terminal,
wherein said positioning management terminal includes: a
positioning object decision section that selects a terminal to be
positioned which is a positioning object and a positioning standard
terminal whose position is known from among said wireless
terminals; a positioning management section that requires distance
information between said terminal to be positioned and said
positioning standard terminal; a position calculation section that
calculates the position of said terminal to be positioned; and a
storage section that keeps an adjacent terminal list that wireless
signals of said wireless terminal reach, said wireless terminal
includes a distance measurement section that measures the distance
from an adjacent terminal that wireless signals of said wireless
terminal reach and a communication section that transmits
measurement results of said distance measurement section to said
positioning management terminal; and wherein said positioning
management section requires distance information from said
positioning standard terminal selected by said positioning object
decision section to said terminal to be positioned selected by said
positioning object decision section, and said position calculation
section calculates the position of said terminal to be positioned
using the distance information and position information of said
positioning standard terminal.
2. The wireless terminal positioning system of claim 1, wherein
said positioning object decision section repeatedly selects said
terminal to be positioned and said positioning standard terminal
until said position calculation section calculates positions of all
said wireless terminals, and said positioning management section
requires distance information between said terminal to be
positioned and said positioning standard terminal for each
repetition.
3. The wireless terminal positioning system of claim 1, wherein
when said position calculation section calculates N-dimension
coordinates of said terminal to be positioned, said positioning
object decision section selects said wireless terminal having at
least N+1 said adjacent terminals whose positions are known as said
terminal to be positioned, and selects at least said N+1 said
adjacent terminals as said positioning standard terminals.
4. The wireless terminal positioning system of claim 1, wherein
said wireless terminal includes an adjacent terminal search section
that searches the adjacent terminal that wireless signals reach,
said positioning management terminal requires an adjacent terminal
list of the wireless terminal to said wireless terminal, said
adjacent terminal search section searches the adjacent terminal of
the relevant wireless terminal based on the request to transmit the
resultant adjacent terminal list to said positioning management
terminal, and said positioning management terminal stores the
adjacent terminal list in said storage section.
5. The wireless terminal positioning system of claim 4, wherein
said positioning management section requires an adjacent terminal
list of the wireless terminal to said wireless terminal, said
positioning object decision section selects said positioning
standard terminal among wireless terminals contained in the
adjacent terminal list.
6. The wireless terminal positioning system of claim 1, wherein
said storage section stores position information of said wireless
terminal and distance information from said wireless terminal to
said adjacent terminal, and said positioning object decision
section calculates a precision index value of said position
information based on said position information and said distance
information.
7. The wireless terminal positioning system of claim 6, wherein
said positioning object decision section calculates a distance
between a position shown by position information of said wireless
terminal and a position shown by position information of said
adjacent terminal of the wireless terminal based on each position
information, and obtains distance information from the wireless
terminal to said adjacent terminal from said storage section to
calculate a precision index value of said position information
based on a difference of the both.
8. The wireless terminal positioning system of claim 6, wherein
said positioning object decision section selects said terminal to
be positioned or said positioning standard terminal so that the
precision index value of said position information becomes the
highest.
9. The wireless terminal positioning system of claim 1, wherein
said positioning management section requires distance information
between the wireless terminal and the adjacent terminal to said
wireless terminal, said position calculation section calculates a
relative position of the relevant wireless terminal using the
distance information.
10. The wireless terminal positioning system of claim 1, wherein,
after said position calculation section calculates positions of all
said wireless terminals, said positioning management section
requires distance information from other wireless terminals to any
of said wireless terminals, and said position calculation section
re-calculates positions of said wireless terminals using the
distance information.
11. The wireless terminal positioning system of claim 1, wherein
said positioning management terminal includes a second distance
positioning section that measures the distance from an adjacent
terminal that wireless signals of the relevant positioning
management terminal reaches, and said position calculation section
calculates the position of the relevant positioning management
terminal using distance information measured by said second
distance measurement section and position information of said
positioning standard terminal.
12. The wireless terminal positioning system of claim 1, wherein
said positioning management terminal includes a second adjacent
terminal search section that searches the adjacent terminal that
wireless signals reach, and said second adjacent terminal search
section stores the adjacent terminal list obtained by searching to
said storage section.
13. The wireless terminal positioning system of claim 1, wherein
said distance measurement section measures the distance between
said wireless terminals using a radio wave propagation time of the
wireless signal.
14. The wireless terminal positioning system of claim 13, wherein
said communication section uses an ultra wideband signal that
transmits an impulse signal for the wireless signal in use when
said distance measurement section measures the distance between
said wireless terminals.
15. The wireless terminal positioning system of claim 1, wherein
said communication section performs multi-hop communication.
16-20. (canceled)
21. An environment measurement system that measures environmental
conditions of a measurement object space, comprising: a fixed
sensor terminal fixedly installed in said measurement object space;
a mobile sensor terminal that moves in said measurement object
space; and measurement means that measures the position of said
mobile sensor terminal, wherein said fixed sensor terminal measures
environmental conditions neighboring an installation location of a
self-terminal, said fixed sensor terminal and said mobile sensor
terminal transmit or receive signals that perform positioning of
the position of said mobile sensor terminal by wireless
communication, said positioning means performs positioning of the
position of said mobile sensor terminal using the signals, and said
mobile sensor terminal measures environmental conditions
neighboring the self-terminal while grasping the position of the
self-terminal in said measurement object space using the
positioning results.
22. The environment measurement system of claim 21, wherein said
mobile sensor terminal holds &list of measurement points whose
environmental conditions in said measurement object space should be
measured, selects the measurement point whose environmental
conditions needs to be measured next from said list, decides
movement amount of the self-terminal from the measurement point and
the current position of the self-terminal based on positioning
results of said positioning means to move to the measurement point,
and measures environmental conditions of the relevant measurement
point.
23. The environment measurement system of claim 21, wherein said
mobile sensor terminal selects a measurement point whose distance
from at least three or more said fixed sensor terminals is less
than a predetermined threshold value as the measurement point whose
environment conditions needs to be measured next when selecting the
measurement point whose environment conditions needs to be measured
next from said list.
24. The environment measurement system of claim 21, wherein said
fixed sensor terminal is installed in a region where said mobile
sensor terminal has to measure environment conditions more
frequently than the region where said mobile sensor terminal
measures environment conditions.
25. An environment measurement system that measures environmental
conditions of a measurement object space, comprising: a plurality
of mobile sensor terminals that move in said measurement object
space; and positioning means that measures the positions of said
mobile sensor terminals, wherein said positioning means selects one
of said mobile sensor terminals as a position detection object
terminal, and at the same time, selects other mobile sensor
terminals as position detection standard terminals, said position
detection object terminal and said position detection standard
terminals transmit or receive signals for positioning of said
position detection object terminal through wireless communication,
said positioning means uses the signal to position said position
detection object terminal, and said position detection object
terminal measures environment conditions neighboring the
self-terminal while grasping the position of the self-terminal in
said measurement object space using the positioning results.
26. The environment measurement system of claim 25, wherein said
position detection object terminal holds a list of measurement
points whose environmental conditions needs to be measured in said
measurement object space, selects the measurement point whose
environmental conditions needs to be measured from said list,
decides the movement amount of the self-terminal from the
measurement point and the current position of the self-terminal
based on positioning results of said positioning means to move to
the measurement point, and measures environmental conditions of the
relevant measurement point.
27. The environment measurement system of claim 25, wherein said
position detection object terminal selects the measurement point
whose distances from at least three said position detection
standard terminals are a predetermined value or less as a
measurement point whose environmental conditions needs to be
measured next when selecting a measurement point whose
environmental conditions needs to be measured next from said
list.
28. The environment measurement system of claim 25, wherein said
positioning means selects said mobile sensor terminal located
furthest from the measurement point as said position detection
object terminal after said position detection object terminal
decides the measurement point whose environmental conditions needs
to be measured next.
29. The environment measurement system of claim 25, wherein said
positioning means reselects one of said mobile sensor terminals as
the position detection object terminal and reselects other mobile
sensor terminals as position detection object terminals after said
position detection standard terminal measures environmental
conditions neighboring the self-terminal.
30. The environment measurement system of claim 25, wherein said
positioning means selects at least three said mobile sensor
terminals whose distance from the measurement point is a
predetermined threshold value or less as the position detection
standard terminal after said position detection object terminal
decides the measurement point whose environmental conditions needs
to be measured next.
31. The environment measurement system of claim 21, wherein said
mobile sensor terminal holds a list in which a typical point of
each region is made to be said measurement point as the list of the
measurement point whose environmental conditions needs to be
measured in said measurement object space upon partitioning said
measurement object space into a lattice-shape region of a
predetermined interval.
32. The environment measurement system of claim 21, wherein said
mobile sensor terminal holds a list in which a typical point of
said lattice-shape region where no fixedly installed fixed sensor
terminal exists is made to be the measurement point as the list of
the measurement point whose environmental conditions needs to be
measured in said measurement object space upon partitioning said
measurement object space into a lattice-shape region of a
predetermined interval.
33. The environment measurement system of claim 21, wherein said
mobile sensor terminal includes a mobile cart capable of moving on
the two-dimension plane and a support table that supports a sensor
for measuring environmental conditions of said measurement object
space, and a plurality of said sensors are provided on said support
table along a vertical direction.
34. The environment measurement system of claim 21, wherein each
said sensor terminal performs wireless communication using an ultra
wide band wireless signal.
35. The environment measurement system of claim 21, wherein said
positioning means detects the position of said mobile sensor
terminal based on any of a received radio wave intensity, a radio
wave propagation time, or a radio wave propagation time difference,
or a combination thereof.
36. A facility management system, comprising: the environment
measurement system of claim 21, and a facility management apparatus
that controls operation of facility equipment, wherein said
facility management apparatus obtains measurement data of
environmental conditions measured by said environment measurement
system to control the operation of said facility equipment based on
the measurement data.
37-39. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a wireless terminal
positioning system that calculates the position of a wireless
terminal and a method of the calculation, and to a technique that
measures environmental conditions.
BACKGROUND ART
[0002] In a small-scale wireless network system supposed to be used
mainly in a building facility and in a home such as a sensor
network system, a technique has been developed that measures the
position of a wireless communication terminal with high
precision.
[0003] Since a GPS (Global Positioning System) signal cannot be
received in the building facility and in the home, a system is
known that measures a distance and a distance difference among a
plurality of terminals to estimate the position using a time of
arrival (TOA) of radio waves from a base station whose position is
known, a time difference of arrival (TDOA) of radio waves, and a
radio wave receiving intensity.
[0004] An assumption is made that coordinates of a base station are
known in advance in the above. In order to save time and effort to
set coordinates of the base station, a technique is proposed such
that "at least (N+1) base stations (N=1 to 3) and positioning
servers are provided. The distances among at least (N+1) base
stations are calculated. Relative coordinates of each base station
are obtained. The obtained relative coordinates are evaluated. A
switching to the terminal positioning processing for obtaining the
position of the terminal is judged. The position of the terminal is
obtained using a propagation time of the wireless signal that is
transmitted and received between the terminal and the base station
and relative coordinates among the obtained base stations."
[0005] On the other hand, in a wireless communication system in
which a number of terminals are installed for buildings and homes
in general, since an output is suppressed so as to be able to be
driven by batteries, causing a limit in a communication range to be
from approximately several meters to several tens of meters.
[0006] As a result, like ZigBee (trademark), for example, a
multi-hop network technique is known that enables communications in
a wider area in which an intermediate communication terminal relays
data for terminals to which no radio waves can reach directly.
[0007] In recent years, in buildings and factories, sensors are
installed at various locations and an environment measurement
system is employed that measures environmental conditions such as
temperature, humidity, and luminance in order to properly control
air conditioning and lighting apparatuses. For example, in an air
conditioning system, an air conditioning apparatus is controlled
such that the measurement value of a temperature sensor installed
at the air supply opening and the remote controller of the indoor
unit of the air conditioning apparatus becomes a set
temperature.
[0008] Further, in order to carefully control the apparatus
according to the request by residents and the temperature
distribution of the space, and to precisely evaluate energy
performance of the building, environmental conditions need to be
measured at more measurement points.
[0009] In order to measure environmental conditions at a number of
measurement points, in general, a number of sensors need to be
installed at a number of places by increasing the number of sensors
to be measured. Therefore, increase in cost and complicated
management become challenges.
[0010] In relation to the above environment measurement, as a
technique intended "to improve precision and accuracy of plant
diagnosis and reduce variations in inspection by making the sensor
to be self-advancing to obtain a number of process values at many
points in order to measure the facility in the plant and process
values of the area", such a technique is proposed that "a sensor
detects the facility constituting a plant or a process value of a
predetermined area. The sensor is provided with drive means that
moves to a desired position in the facility or a predetermined area
to detect process values." (Patent Literature 2) [0011] Patent
Literature 1 Japanese Unexamined Patent Application Publication No.
2007-248362 [0012] Patent Literature 2 Japanese Unexamined Patent
Application Publication No. 2003-130695
SUMMARY OF INVENTION
Technical Problem
[0013] According to a conventional method, in a system where a
number of communication terminals are installed having low output
over a wide area and communication is performed by relaying in the
middle to terminals incapable of direct communication, a number of
base stations to be a standard for positioning need to be installed
so as to cover the area where the network system is installed.
[0014] In a method that automatically obtains a relative position
between base stations like the above Patent Literature 1, all the
base stations need to communicate each other, therefore, it is
difficult to decide the relative position of the base station in
the area beyond a communication range of a base station.
[0015] The self-advancing sensor according to the above Patent
Literature 2 moves along piping and runs on a rail laid in advance.
Accordingly, a rail guide and the like to be a reference when
controlling a moving position of the self-advancing sensor has to
be installed in advance, resulting costly.
[0016] The present invention is done to solve the above problems
and its object is to obtain a method for positioning a wireless
terminal capable of obtaining the position of each communication
terminal by measuring a distance among installed communication
terminals with no base station being installed fixedly.
[0017] Another object is to provide a method for measuring
environmental conditions at a number of measurement points with
less cost by a few sensor terminals.
Solution to Problem
[0018] A wireless terminal positioning system according to the
present invention has a positioning management terminal that
manages one or a plurality of wireless terminals and the
positioning of the wireless terminals. The positioning management
terminal includes: a positioning object decision section that
selects a terminal to be positioned, which is a positioning object,
and a positioning standard terminal, whose position is known, among
the above wireless terminals; a positioning management section that
requires distance information between the terminal to be positioned
and the positioning standard terminal; and a position calculation
section that calculates the position of the terminal to be
positioned. The wireless terminal includes a distance measurement
section that measures the distance from the adjacent terminal at
which wireless signals of the wireless terminal arrives, and a
communication section that transmits measurement results of the
distance measurement section to the positioning management
terminal. The positioning management terminal requires distance
information from the positioning standard terminal selected by the
positioning object decision section to the terminal to be
positioned selected by the positioning object decision section. The
position calculation section calculates the position of the
terminal to be positioned using the distance information and
position information of the positioning standard terminal.
[0019] An environment measurement system according to the present
invention measures environmental conditions of a measurement object
space. There are provided: a fixed sensor terminal fixedly
installed in the measurement object space; a mobile sensor terminal
that moves in the measurement object space; and positioning means
that measures the position of the mobile sensor terminal. The fixed
sensor terminal measures environmental conditions surrounding the
installation place of the self terminal. The fixed sensor terminal
and the mobile sensor terminal transmit or receive signals for
positioning the mobile sensor terminal. The positioning means
positions the mobile sensor terminal using the signals. The mobile
sensor terminal measures environmental conditions around the self
terminal while grasping the position of the self terminal in the
measurement object space using the positioning results.
Advantageous Effects of Invention
[0020] In the wireless terminal positioning system according to the
present invention, a terminal to be positioning and a positioning
standard terminal are selected in order and distance information is
obtained. Based on the position information, the position of the
wireless terminal is calculated.
[0021] Accordingly, there is no need to install a base station
fixedly. Wireless terminals measure distance each other in order
and distance information is collected, thus enabling to obtain
positions of wireless terminals installed over a wide range.
[0022] In the environment measurement system according to the
present invention, the mobile sensor terminal measures
environmental conditions while grasping the position of the self
terminal to move in the measurement object space. Thereby, it
becomes possible to measure environmental conditions of a number of
measurement points only by a few mobile sensor terminals while
moving.
[0023] Since a fixed sensor terminal is available as a standard of
position detection, there is no need to lay a guide such as a rail
for controlling movement position of the mobile sensor terminal,
being advantageous over cost.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 is a configuration diagram of a wireless positioning
system of Embodiment 1.
[0025] FIG. 2 is a function block diagram of a positioning
management terminal 100 of Embodiment 1.
[0026] FIG. 3 is a function block diagram of a wireless terminal
200 of Embodiment 1.
[0027] FIG. 4 is an illustration diagram of procedure in which a
distance measurement section 220 of the wireless terminal 200
performs distance measurement.
[0028] FIG. 5 is a configuration diagram of a range-finding data
request packet 500.
[0029] FIG. 6 is a configuration diagram of a range-finding data
response packet 600.
[0030] FIG. 7 is a configuration diagram of a wireless terminal
list 700 that a terminal information storage section 150
stores.
[0031] FIG. 8 is a conceptual diagram showing a state in which the
position of the wireless terminals 200 is determined in order in
the wireless positioning system of Embodiment 1.
[0032] FIG. 9 is an entire operation sequence of the wireless
positioning system of Embodiment 1.
[0033] FIG. 10 is a flow chart illustrating details of step S901 of
FIG. 9.
[0034] FIG. 11 is a function block diagram of the wireless terminal
of Embodiment 2.
[0035] FIG. 12 is an operation sequence diagram when the wireless
terminal 200a receives an adjacent terminal data request packet
1300.
[0036] FIG. 13 is a configuration diagram of the adjacent terminal
data request packet 1300.
[0037] FIG. 14 is a configuration diagram of an adjacent terminal
data response packet 1400.
[0038] FIG. 15 is a flow chart of positioning procedure of
Embodiment 2.
[0039] FIG. 16 is a configuration diagram of the wireless
positioning system of Embodiment 3.
[0040] FIG. 17 is a function block diagram of a mobile wireless
terminal 300.
[0041] FIG. 18 is an entire operation sequence of the wireless
positioning system of Embodiment 3.
[0042] FIG. 19 is a sequence diagram showing procedure in which
relative positions of the wireless terminals 200 of (N+1) or more
are obtained and stored in position information 702.
[0043] FIG. 20 is a configuration diagram of an environment
measurement system of Embodiment 15.
[0044] FIG. 21 is a functional block diagram of a fixed sensor
terminal 101.
[0045] FIG. 22 is a functional block diagram of a mobile sensor
terminal 2200.
[0046] FIG. 23 is a diagram illustrating procedure for a wireless
positioning section 2213 to calculate the distance between the
mobile sensor terminal 2200 and a fixed sensor terminal 2100.
[0047] FIG. 24 is a diagram illustrating a method for the wireless
positioning section 2213 to calculate the position of the mobile
sensor terminal 2200.
[0048] FIG. 25 is an operation flow for the mobile sensor terminal
2200 to measure environmental conditions.
[0049] FIG. 26 is a configuration diagram of an environment
measurement system of Embodiment 16.
[0050] FIG. 27 is a configuration diagram of an environment
measurement system of Embodiment 17.
[0051] FIG. 28 is a diagram illustrating the state in which the
mobile sensor terminal 2200 switches a role of the self
terminal.
[0052] FIG. 29 is an operation flow for a position detection object
terminal 2902 to measure environmental conditions.
[0053] FIG. 30 is a diagram showing the state in which a
measurement object space is divided.
[0054] FIG. 31 is a configuration diagram of the mobile sensor
terminal 2200 of Embodiment 21.
[0055] FIG. 32 is a configuration diagram of a facility management
system of Embodiment 22.
REFERENCE SIGNS LIST
[0056] 100 positioning management terminal [0057] 110 communication
section [0058] 120 positioning procedure management section [0059]
130 positioning object decision section [0060] 140 position
calculation section [0061] 150 terminal information storage section
[0062] 200a-200j wireless terminal [0063] 210 communication section
[0064] 220 distance measurement section [0065] 230 range-finding
data processing section [0066] 240 adjacent terminal search section
[0067] 250 adjacent terminal data processing section [0068] 300
mobile wireless terminal [0069] 500 range-finding data request
packet [0070] 501 range-finding data request identifier [0071] 502
transmission source terminal address [0072] 503 terminal address to
be positioned [0073] 504 number of range-finding terminal [0074]
505 range-finding object terminal address [0075] 600 range-finding
data response packet [0076] 601 range-finding data response
identifier [0077] 602 terminal address to be positioned [0078] 603
transmission destination terminal address [0079] 604 number of
range-finding terminal [0080] 605 range-finding object address
[0081] 606 range-finding information [0082] 700 wireless terminal
list [0083] 701 terminal address [0084] 702 position information
[0085] 703 adjacent terminal list [0086] 704 terminal address
[0087] 705 distance information [0088] 1300 adjacent terminal data
request packet [0089] 1301 adjacent terminal data request
identifier [0090] 1302 transmission source terminal address [0091]
1303 search source terminal address [0092] 1400 adjacent terminal
data response packet [0093] 1401 adjacent terminal data response
identifier [0094] 1402 search source terminal address [0095] 1403
transmission destination terminal address [0096] 1404 number of
adjacent terminal [0097] 1405 adjacent terminal address [0098] 2100
fixed sensor terminal [0099] 2100a-2100c fixed sensor terminal
[0100] 2110 terminal control section [0101] 2111 wireless
communication section [0102] 2112 environment measurement section
[0103] 2200 mobile sensor terminal [0104] 2210 terminal control
section [0105] 2211 wireless communication section [0106] 2212
environment measurement section [0107] 2213 wireless positioning
section [0108] 2214 self position control section [0109] 2215 drive
section [0110] 2701 window [0111] 2702 gateway [0112] 2901 position
detection standard terminal [0113] 2902 position detection object
terminal [0114] 3101 typical point [0115] 3201 mobile cart [0116]
3202 control module [0117] 3203 support table [0118] 3204 sensor
module [0119] 3300 facility management apparatus [0120] 3301
facility management section [0121] 3302 wireless communication
section
DESCRIPTION OF EMBODIMENTS
Embodiment 1
[0122] FIG. 1 is a configuration diagram of a wireless positioning
system of Embodiment 1.
[0123] The wireless positioning system of Embodiment 1 includes one
or a plurality of positioning management terminals 100 and wireless
terminals 200a to 200j.
[0124] The positioning management terminal 100 manages a
positioning process that measures positions of wireless terminals
200a to 200j. Specific procedures will be described using FIGS. 8
to 10 to be mentioned later.
[0125] The wireless terminals 200a to 200j are a communication
terminal having a wireless communication function.
[0126] In the following description, alphabetical subscripts will
be added when differentiating the wireless terminals 200a to 200j.
In a generic explanation, they are called a wireless terminal 200.
Each function section provided with the wireless terminal 200 is
the same.
[0127] FIG. 2 is a function block diagram of a positioning
management terminal 100 of Embodiment 1.
[0128] A positioning management terminal 100 includes a
communication section 110, a positioning procedure management
section 120, a positioning object decision section 130, a position
calculation section 140, and a terminal information storage section
150.
[0129] The communication section 110 performs wireless
communication with the wireless terminal 200.
[0130] The terminal information storage section 150 holds a
wireless terminal list 700 in the wireless positioning system. The
wireless terminal list 700 will he described again in FIG. 7 to be
mentioned later.
[0131] The position calculation section 140 calculates a position
in the Nth-dimension space of the wireless terminal 200, that is
Nth-dimension coordinates, from distances between at least (N+1)
wireless terminals 200 (N is a dimension of the position to be
calculated, N=1 to 3) whose positions are known and the wireless
terminal 200 to be the object for deciding the position.
[0132] In the following explanations, the wireless terminal 200
whose position is known is referred to as a "positioning standard
terminal" and the wireless terminal 200 to be an object for
deciding the position is referred to as a "terminal to be
positioned".
[0133] A positioning procedure management section 120 and a
positioning object decision section 130 specify which wireless
terminals 200 are to be the positioning standard terminal and the
terminal to be positioned. Details will be described later.
[0134] The positioning procedure management section 120 manages
communication with each wireless terminal 200 for positioning,
position calculation of the wireless terminal 200 by a position
calculation section 140, and procedure like selection of the
positioning standard terminal and the terminal to be positioned by
the positioning object decision section 130 to manage positioning
operation in the present wireless positioning system.
[0135] The positioning object decision section 130 decides the
wireless terminal 200 to be an object for next positioning and the
wireless terminal 200 (positioning standard terminal) to be a
standard for positioning when the wireless terminal 200 is made to
be the terminal to be positioned.
[0136] As for a decision technique to decide which wireless
terminal be the terminal to be positioned and the positioning
standard terminal, descriptions will be given later.
[0137] FIG. 3 is a function block diagram of a wireless terminal
200 of Embodiment 1.
[0138] The wireless terminal 200 includes a communication section
210, a distance measurement section 220, and a range-finding data
processing section 230.
[0139] The communication section 210 performs wireless
communication with the positioning management terminal 100 and
other wireless terminals 200.
[0140] The distance measurement section 220 measures the distance
between two wireless terminals 200 using wireless communication.
Procedure for distance measurement between wireless terminals 200
will be explained in FIG. 4 to be mentioned later.
[0141] The range-finding data processing section 230 transmits and
receives range-finding data request packet and range-finding
response packet between the wireless terminal 200 and the
positioning management terminal 100 via the communication section
210. Further, the section 230 transmits and receives range-finding
data request packet and range-finding response packet in FIG. 4 to
be mentioned later.
[0142] The range-finding data processing section 230 can deliver
range-finding data request packet and range-finding response packet
via the communication section 210 to the wireless terminal 200 and
the positioning management terminal 100 to which no wireless signal
is directly delivered by a multi-hop communication.
[0143] The communication section 110 of the positioning management
terminal 100 and the communication section. 210 of the wireless
terminal 200 perform packet communication with the positioning
management terminal 100 or the wireless terminal 200 to which
wireless signals are directly delivered.
[0144] The communication section 210 makes it possible to transfer
packets to the positioning management terminal 100 and the wireless
terminal 200 to which no wireless signal is directly delivered by
relaying packets to other wireless terminals 200 to transmit
them.
[0145] In order to relay packets to the positioning management
terminal 100 and the wireless terminal 200 to which no wireless
signal is directly delivered, the communication section 110 and the
communication section 210 utilize a multi-hop network protocol such
as ZigBee.
[0146] FIG. 4 is an illustration diagram of procedure in which the
distance measurement section 220 of the wireless terminal 200
performs distance measurement. Here, an example is given in which
the wireless terminal 200a measures the distance from the wireless
terminal 200b. Descriptions will be given to each step of FIG. 4 as
follows.
[0147] (S401)
[0148] The distance measurement section 220a of the wireless
terminal 200a transmits a range-finding request packet to the
wireless terminal 200b via the communication section 210.
[0149] On receiving the range-finding request packet, the distance
measurement section 220b of the wireless terminal 200b transmits a
range-finding response packet to the wireless terminal 200a after a
predetermined processing time being elapsed.
[0150] On receiving the range-finding response packet, the distance
measurement section 220a of the wireless terminal 200a measures a
response time from the transmission of the range-finding request
packet to the receipt of the range-finding response packet.
[0151] Time measurement from the transmission of the range-finding
request packet to the receipt of the range-finding response packet
is performed such that a counter timer is started when transmitting
the range-finding request packet, the counter is stopped when
receiving the range-finding response packet, then the time value of
the counter is read.
[0152] (S402)
[0153] The distance measurement section 220a of the wireless
terminal 200a subtracts a predetermined processing time of the
wireless terminal 200b from the receipt of the range-finding
request packet to the transmission of the range-finding response
packet based on the response time in step S401 to calculate a radio
wave propagation time between the wireless terminals 200a and
200b.
[0154] (S403)
[0155] The distance measurement section 220a of the wireless
terminal 200a obtains the distance between the wireless terminals
200a and 200b by multiplying the radio wave propagation time by the
speed of light.
[0156] When transmitting and receiving range-finding request and
range-finding response, the communication section 210 can measure
more accurate distance because using a ultra wide band impulse
wireless signal that transmits an impulse signal, response time can
be measured accurately.
[0157] FIG. 5 is a configuration diagram of the range-finding data
request packet 500. The range-finding data request packet 500 is
the packet that is intended to request transmission of
range-finding results of the wireless terminal 200 that received
the packet 500.
[0158] The range-finding data request packet 500 includes a
range-finding data request identifier 501, a transmission source
terminal address 502, a terminal address 503 to be positioned, a
number 504 of range-finding terminal, and a range-finding object
terminal address 505.
[0159] In the range-finding data request identifier 501, an
identifier is stored that shows that the relevant packet is the
range-finding data request packet.
[0160] In the transmission source terminal address 502, the
transmission source terminal address of the relevant packet is
stored.
[0161] In the terminal address 503 to'be positioned, the terminal
address to be positioned is stored.
[0162] In the number 504 of range-finding terminal, the number of
terminals of range-finding object is stored.
[0163] In the range-finding object terminal address 505, the
range-finding object terminal address is stored for as many as the
number shown by the number 504 of range-finding terminal.
[0164] FIG. 6 is a configuration diagram of the range-finding data
response packet 600. The range-finding data response packet 600 is
the response packet corresponding to the range-finding data request
packet 500.
[0165] The range-finding data response packet 600 includes a
range-finding data response identifier 601, a terminal address to
be positioned 602, a transmission destination terminal address 603,
a number 604 of range-finding terminal, a range-finding object
terminal address 605, and range-finding information 606.
[0166] In the range-finding data response identifier 601, an
identifier is stored that shows that the relevant packet is the
range-finding data response packet.
[0167] In the terminal address to be positioned 602, the terminal
address to be positioned is stored.
[0168] In the transmission destination terminal address 603, the
transmission destination terminal address of the relevant packet is
stored.
[0169] In the number 604 of range-finding terminal, the number of
terminals of range-finding object is stored.
[0170] In the range-finding object terminal address 605, the
range-finding object terminal address is stored for as many as the
number shown by the number 604 of range-finding terminal.
[0171] In the range-finding information 606, range-finding results
are stored for each range-finding object terminal.
[0172] When the wireless terminal 200 receives the range-finding
request packet, the distance measurement section 220 performs
range-finding between the wireless terminals 200 designated by the
range-finding object terminal address 505 of the range-finding
request packet.
[0173] Next, the range-finding data processing section 230
generates the range-finding response packet to transmit it to the
transmission source of the range-finding request packet based on
the range-finding results performed by the distance measurement
section 220.
[0174] FIG. 7 is a configuration diagram of a wireless terminal
list 700 that a terminal information storage section 150
stores.
[0175] The wireless terminal list 700 includes a terminal address
701, position information 702, and an adjacent terminal list
703.
[0176] The adjacent terminal list 703 includes a terminal address
704 and distance information 705.
[0177] In the terminal address 701, the address of the wireless
terminal list 700 is stored. Here, the address is described in a
simple form made only of the number of the wireless terminal.
[0178] In the position information 702, position coordinates of the
wireless terminal 200 are stored identified by the terminal address
701. Here, example is shown in which three-dimension coordinates
are stored.
[0179] In the adjacent terminal list 703, an adjacent terminal list
is stored identified by the terminal address 701.
[0180] In the terminal address 704, the adjacent terminal address
is stored.
[0181] In the distance information 705, the distance between the
adjacent terminal identified by the terminal address 704 and the
relevant wireless terminal.
[0182] In the position information 702, the adjacent terminal list
703, and distance information 705, it is allowable to store that it
is undefined.
[0183] The holding method is not limited thereto if the above
information can be held in full measure.
[0184] The communication section 110, positioning procedure
management section 120, position calculation section 140,
positioning object decision section 130, and terminal information
storage section 150 owned by the positioning management terminal
100 and the communication section 210, distance measurement section
220, and range-finding data processing section 230 owned by the
wireless terminal 200 can be configured using such as an LSI (Large
Scale Integration), ROM (Read Only Memory), and RAM (Random Access
Memory), on which a wireless transmission and reception circuit is
implemented.
[0185] Alternatively, equivalent functions can be configured by
operation devices such as a microcomputer and software specifying
its operation.
[0186] Components of a single positioning management terminal 100
or wireless terminal 200 may be configured by being distributed
into the terminals such as a plurality of microcomputers and
personal computers. It is the same for embodiments below.
[0187] Descriptions have been given to each configuration of the
wireless positioning system according to Embodiment 1 in the
above.
[0188] Next, operations will be explained thereof.
[0189] In the explanation of Embodiment 1 as follows, the terminal
address of the adjacent terminal of each wireless terminal 200 is
supposed to be held in the adjacent terminal list 703 of the
terminal information storage section 150 of the positioning
management terminal 100 in advance.
[0190] The terminal address 701 of the adjacent terminal of each
wireless terminal 200 is configured, for example, by manual input
in advance. Alternatively, all terminals are supposed to be
installed within a area capable of communication, for example, and
the terminal addresses of all the wireless terminals 200 except the
self terminal may be configured for the adjacent terminal list 703
corresponding to each wireless terminal 200.
[0191] Similarly, each wireless terminal 200 is installed in
consideration of the communication distance, and a predetermined
wireless terminal 200 may be configured in the adjacent terminal
list 703.
[0192] In the explanation below, positions of at least (N+1)
wireless terminals 200 are supposed to be configured in the
position information 702 of the corresponding terminal address 701
in the terminal information storage section 150 of the positioning
management terminal 100.
[0193] Alternatively, positions of (N+1) or more wireless terminals
200 are decided in advance, and each wireless terminal 200 may be
placed at that position. Among a plurality of the placed wireless
terminals 200, positions of (N+1) or more terminals may be manually
input and configured.
[0194] FIG. 8 is a conceptual diagram showing a state in which the
position of each wireless terminal 200 is determined in order in
the wireless positioning system of Embodiment 1. The positioning
management terminal 100 is abbreviated.
[0195] The upper diagram of FIG. 8 shows the adjacent terminal list
703c of a certain wireless terminal 200c whose terminal address 701
is "3" at the time of a k-th positioning. The terminal to be
positioned and the positioning standard terminal selected by the
positioning management terminal 100 are shown as well.
[0196] The lower diagram of FIG. 8 shows the adjacent terminal list
703d of the wireless terminal 200d whose terminal address 701 is
"4" at the time of the (k+1)-th positioning as well. The terminal
to be positioned and the positioning standard terminal selected by
the positioning management terminal 100 are shown by signs in the
diagram.
[0197] In the k-th state (upper diagram of FIG. 8), position
information 702 of the wireless terminals 200b, 200e, 200f, and
200i of the terminal addresses [2], [5], [6], and [9] is defined
(the terminal in banding pattern) in the adjacent terminal list
703c of the wireless terminal 200c whose terminal address 701 is
"3".
[0198] That is, upon calculating the three-dimension coordinates,
position information of at least 3+1=4 adjacent terminals has been
defined.
[0199] Therefore, the positioning object decision section 130 of
the positioning management terminal 100 selects the wireless
terminal 200c whose terminal address is "3" as the terminal to be
positioned (a filled terminal) The wireless terminals 200b, 200e,
200f, and 200i of the terminal addresses [2], [5], [6], and [9] are
selected as positioning standard terminals (the terminal in banding
pattern).
[0200] The positioning procedure management section 120 of the
positioning management terminal 100 obtains distance information
705 between the terminal to be positioned (the wireless terminal
200c) and the positioning standard terminals (the wireless
terminals 200b, 200e, 200f, and 200i). The position calculation
section 140 calculates the position of the terminal to be
positioned (the wireless terminal 200c) using the distance
information 705.
[0201] Similarly, in the (k+1)-th state at the time of positioning,
position information 702 of the wireless terminals 200b, 200c,
200e, and 200f of the terminal addresses [2], [3], [5], and [6] is
defined (the terminal in banding pattern) in the adjacent terminal
list 703d of the wireless terminal 200d whose terminal address 701
is "4".
[0202] Therefore, the positioning object decision section 130 of
the positioning management terminal 100 selects the wireless
terminal 200d whose terminal address 701 is "4" as the terminal to
be positioned (a filled terminal). The wireless terminals 200b,
200c, 200e, and 200f of the terminal addresses [2], [3], [5], and
[6] are selected as positioning standard terminals (the terminal in
banding pattern).
[0203] The positioning procedure management section 120 of the
positioning management terminal 100 obtains distance information
705 between the terminal to be positioned (the wireless terminal
200d) and the positioning standard terminals (the wireless
terminals 200b, 200c, 200e, and 200f). The position calculation
section 140 calculates the position of the terminal to be
positioned (the wireless terminal 200d) using the distance
information 705.
[0204] FIG. 9 is an entire operation sequence of the wireless
positioning system of Embodiment 1.
[0205] Descriptions will be given to each step of FIG. 9. Here,
each operation under the state of the upper diagram of FIG. 8 will
be explained as an example.
[0206] (S901)
[0207] The positioning object decision section 130 of the
positioning management terminal 100 refers to information of the
wireless terminal list 700 that the terminal information storage
section 150 holds to select the next object to be positioned as the
terminal to be positioned among the wireless terminals 200 whose
position information 702 is undefined in the wireless terminal list
700. In the example of FIG. 8, for example, the wireless terminal
200c is selected.
[0208] The positioning object decision section 130 selects at least
(N+1) positioning standard terminals for positioning the terminal
to be positioned among the wireless terminals 200 whose position
information 702 is defined in the wireless terminal list 700.
[0209] (S902)
[0210] The positioning procedure management section 120 transmits
the range-finding data request packet 500 to the terminal to be
positioned (the wireless terminals 200c) notified by the
positioning object decision section 130 via the communication
section 110.
[0211] In the range-finding object terminal address 505 of the
range-finding data request packet 500, the terminal address of the
positioning standard terminal (the wireless terminals 200b, 200e,
200f, and 200i) notified by the positioning object decision section
130 is stored.
[0212] (S903a to S903d)
[0213] The distance measurement section 220c of the terminal to be
positioned (the wireless terminals 200c) that received the
range-finding data request packet 500 performs positioning in order
for the positioning standard terminals (here, the wireless
terminals 200b, 200e, 200f, and 200i) stored in the range-finding
object terminal address 505 of the range-finding data request
packet 500.
[0214] The range-finding data processing section 230c collectively
stores positioning results of the distance measurement section 220c
into the range-finding data response packet 600 to transmit them to
the positioning management terminal 100.
[0215] (S904)
[0216] The position calculation section 140 of the positioning
management terminal 100 obtains the position information 702 of the
positioning standard terminal selected by the positioning object
decision section 130 and the distance information 705 between the
terminal to be positioned and the positioning standard terminal
selected by the positioning object decision section 130.
[0217] Next, the position calculation section 140 calculates the
position of the terminal to be positioned (the wireless terminal
200) using the position information 702 and the distance
information 705.
[0218] Calculated position of the terminal to be positioned (the
wireless terminal 200) is stored in the position information 702
corresponded by the terminal information storage section 150.
[0219] According to the above procedure (S902 to S904), the
position of the terminal to be positioned (the wireless terminal
200) selected by the positioning object decision section 130 is
decided.
[0220] (S905)
[0221] The positioning procedure management section 120 judges
whether the position information 702 of all the wireless terminals
200 in the wireless terminal list 700 has been defined or not.
[0222] If the position information 702 of all the wireless
terminals 200 has been defined, the positioning procedure
management section 120 concludes positioning. If the position
information 702 of all the wireless terminals 200 has not been
defined, the process returns to step S901 to repeat the same
processing.
[0223] FIG. 10 is a flow chart illustrating details of step S901 of
FIG. 9. Descriptions will be given to each step of FIG. 10.
[0224] (S1001)
[0225] The positioning object decision section 130 of the
positioning management terminal 100 selects the wireless terminals
200 in order in the wireless terminal list 700 stored by the
terminal information storage section 150.
[0226] (S1002)
[0227] The positioning object decision section 130 judges whether
the position information 702 of the wireless terminals 200 selected
in step S1001 has been defined or not. If not yet defined, proceed
to step S1003. If defined, return to step S1001 to select the next
wireless terminal 200. This step is intended for searching a
candidate of the terminal to be positioned.
[0228] (S1003)
[0229] With regard to the wireless terminal 200 whose position
information 702 has not been defined, the positioning object
decision section 130 refers to the adjacent terminal list 703 of
the wireless terminal 200. Next, the positioning object decision
section 130 judges whether at least (N+1) or more wireless
terminals 200 whose position information 702 has been defined are
included in the adjacent terminal list 703.
[0230] If (N+1) or more have been defined, proceed to step S1004.
If not, return to step S1001 to select the next wireless terminal
200.
[0231] (S1004)
[0232] The positioning object decision section 130 selects the
wireless terminals 200 whose position information 702 has not been
defined as the terminal to be positioned.
[0233] (S1005)
[0234] The positioning object decision section 130 selects any of
(N+1) wireless terminals 200 among adjacent terminals of the
terminal to be positioned selected in step S1004 as the positioning
standard terminal.
[0235] If (N+1) or more adjacent terminals whose position
information 702 has been defined are not included, the same
judgment as S1001 and S1002 is performed for the next wireless
terminals 200 whose position information 702 has been defined.
[0236] Details of step S901 are explained in the above.
[0237] As described in FIG. 10, by selecting the terminal to be
positioned and the positioning standard terminal, the terminal to
be positioned can be selected that can define the position based on
range-finding data.
[0238] The positioning object decision section 130 informs the
positioning procedure management section 120 of the terminal
addresses 701 of the selected terminal to be positioned and the
positioning standard terminal.
[0239] Operation of the wireless positioning system according to
Embodiment 1 is explained in the above.
[0240] As mentioned above, according to Embodiment 1, the position
of the wireless terminals 200 whose position information 702 has
not been defined is calculated in order by distance information 705
between the wireless terminals 200 whose position information 702
has been defined.
[0241] Thereby, position information 702 of all the wireless
terminals 200 can be calculated.
[0242] According to Embodiment 1, the positioning management
terminal 100 calculates position information 702 of all the
wireless terminals 200 while selecting the positioning standard
terminal and the terminal to be positioned in order.
[0243] Therefore, without separately installing base stations over
a wide area and configuring their positions in advance, it is
possible to calculate position information 702 of each wireless
terminals 200 based on position information of already installed
wireless terminals 200.
[0244] According to Embodiment 1, with the wireless terminals 200
incapable of direct communication with each other, the positioning
management terminal 100 transmits the range-finding data request
packet 500 to the wireless terminals 200 selected as the terminal
to be positioned by a multi-hop communication.
[0245] The wireless terminal 200 that received the range-finding
data request packet 500 transmits the range-finding data response
packet 600 including the measured distance information 606 to the
positioning management terminal 100 again by the multi-hop
communication.
[0246] Thereby, since the positioning management terminal 100 can
finalize position information 702 of the wireless terminals 200 in
order, position information 702 of all the wireless terminals 200
can be decided in the wireless positioning system in which the
wireless terminals 200 are installed over a wide range.
[0247] In Embodiment 1, mutual distance of all the wireless
terminals 200 is not measured but only the distance between the
terminal to be positioned and the positioning standard terminal
selected by the positioning management terminal 100 may be
measured. Thereby, communication amount for range-finding can be
reduced.
[0248] That is, with N wireless terminals 200, frequency of
communication in proportion to N squared is necessary for measuring
the distance among all the adjacent terminals. However, in
Embodiment 1, frequency of communication in proportion to N will
suffice.
[0249] Thus, communication amount can be drastically reduced
required for measuring positions of a number of units.
[0250] In Embodiment 1, the positioning management terminal 100
calculates position information 702 of all the wireless terminals
200 while selecting the positioning standard terminal and the
terminal to be positioned in order.
[0251] Therefore, there is no distinction between the base station
and the terminal to be positioned like a conventional positioning
method.
[0252] Accordingly, by providing devices installed at a suitable
interval in a building facility, for example, with the wireless
terminal 200 according to Embodiment 1, it becomes possible to
obtain the position of each device without separately installing a
base station.
Embodiment 2
[0253] FIG. 11 is a function block diagram of the wireless terminal
200 of Embodiment 2. The wireless terminal 200 of Embodiment 2
newly includes the adjacent terminal search section 240 and the
adjacent terminal data processing section 250 in addition to the
wireless terminal 200 of Embodiment 1. The other configurations are
the same with FIG. 3.
[0254] The adjacent terminal search section 240 obtains information
on the adjacent terminal of the wireless terminal 200. The
procedure to obtain information on the adjacent terminal will be
explained in FIG. 12 to be mentioned later.
[0255] The adjacent terminal data processing section 250 transmits
and receives the adjacent terminal data request packet 1300 and the
adjacent terminal data response packet 1400 described in FIGS. 13
and 14 to be mentioned later with the positioning management
terminal 100. The adjacent terminal data processing section 250
also transmits and receives the adjacent terminal search packet and
the adjacent terminal search response packet described in FIG. 12
to be mentioned later.
[0256] The adjacent terminal data processing section 250 can
deliver the adjacent terminal data request packet 1300 and the
adjacent terminal data response packet 1400 via the communication
section 210 to the wireless terminal 200 and the positioning
management terminal 100 to which no wireless signal is directly
delivered by multi-hop communication.
[0257] On receiving the adjacent terminal data request packet 1300,
the adjacent terminal data processing section 250 of the wireless
terminal 200 stores the address of the adjacent terminal that the
adjacent terminal search section 240 obtained into the adjacent
terminal data response packet 1400 to transmit the same to the
transmission source of the adjacent terminal data request packet
1300.
[0258] The adjacent terminal search section 240 and the adjacent
terminal data processing section 250 can be configured using LSI,
ROM, RAM and the like that implemented a wireless transmission and
reception circuit.
[0259] Alternatively, similar functions can be configured by
operation devices such as microcomputers and software defining
their operations.
[0260] FIG. 12 is an operation sequence diagram when the wireless
terminal 200a receives an adjacent terminal data request packet
1300.
[0261] The adjacent terminal data processing section 250a of the
wireless terminal 200a receives adjacent terminal data request
packet 1300 described in FIG. 13 to be mentioned later through the
communication section 210.
[0262] Next, the adjacent terminal search section 240a transmits
the adjacent terminal search packet by synchronous
transmission.
[0263] The adjacent terminal data processing section 250 of the
wireless terminal 200 (here, 200b to 200d) that received the
adjacent terminal search packet transmits the adjacent terminal
search response packet to the wireless terminal 200a.
[0264] The adjacent terminal search section 240 of the wireless
terminal 200a, which is a search source, holds the transmission
source address of the adjacent terminal search response packet in a
memory, etc.
[0265] Thereby, the wireless terminal 200a can obtain information
on the adjacent terminal of its own.
[0266] Upon receiving the adjacent terminal data request packet
1300, the adjacent terminal search section 240 may correspond to
information of the adjacent terminal obtained by searching the
adjacent terminal, or may respond to the adjacent terminal data
already obtained.
[0267] In the case of a number of adjacent terminals, the adjacent
terminal search section 240 may correspond to the adjacent terminal
information by dividing data into a plural packet.
[0268] FIG. 13 is a configuration diagram of the adjacent terminal
data request packet 1300.
[0269] The adjacent terminal data request packet 1300 includes an
adjacent terminal data request identifier 1301, a transmission
source terminal address 1302, and a search source terminal address
1303.
[0270] In the adjacent terminal data request identifier 1301, an
identifier is stored stating that the relevant packet is the
adjacent terminal data request packet.
[0271] In the transmission source terminal address 1302, the
transmission source terminal address of the relevant packet is
stored.
[0272] In the search source terminal address 1303, the address of
the terminal (the wireless terminal 200a in the example of FIG. 12)
is stored that searches the adjacent terminal by receiving the
relevant packet.
[0273] FIG. 14 is a configuration diagram of a adjacent terminal
data response packet 1400.
[0274] The adjacent terminal data response packet 1400 includes an
adjacent terminal data response identifier 1401, a search source
terminal address 1402, a transmission destination terminal 1403,
number of the adjacent terminal 1404, and an adjacent terminal
address 1405.
[0275] In the adjacent terminal data response identifier 1401, an
identifier is stored stating that the relevant packet is the
adjacent terminal data response packet.
[0276] In the search source terminal address 1402, the terminal
(the wireless terminal 200a in the example of FIG. 12) address is
stored that collected search results of the transmission source of
the relevant packet, that is, the adjacent terminal.
[0277] In the transmission destination terminal 1403, the terminal
address is stored that transmits the transmission destination
terminal of the relevant packet, that is, the adjacent terminal
data request packet 1300.
[0278] In the adjacent terminal number 1404, the number of the
adjacent terminals (three in the example of FIG. 12) of the
wireless terminal is stored that transmits the relevant packet.
[0279] In the adjacent terminal address 1405, the adjacent terminal
(the wireless terminals 200b to 200d in the example of FIG. 12)
address of the wireless terminal is stored that transmits the
relevant packet.
[0280] FIG. 15 is a flow chart of positioning procedure of
Embodiment 2. In the following, each step of FIG. 15 will be
explained.
[0281] (S1501)
[0282] The positioning management terminal 100 transmits the
adjacent terminal data request packet 1300 to all the wireless
terminals 200 to obtain the adjacent terminal information on each
wireless terminal 200 included in the adjacent terminal data
response packet 1400.
[0283] In Embodiment 1, it is assumed that information of the
adjacent terminal has been set in the terminal information storage
section 150 of the positioning management terminal 100 in advance
prior to positioning operation. However, Embodiment 2 is different
from Embodiment 1 in that the present step collects the adjacent
terminal information.
[0284] (S1502) to (S1505)
[0285] The same procedure with the steps S901 to S905 described in
FIG. 9 of Embodiment 1.
[0286] As mentioned above, in Embodiment 2, each wireless terminal
200 is adapted to automatically obtain the adjacent terminal
address through the mutual communication.
[0287] Therefore, after installing the wireless terminal 200,
position information 702 of all the wireless terminals 200 can be
automatically calculated. Accordingly, pre-configuration can be
drastically reduced necessary for obtaining positions of the
wireless terminals 200 installed over a wide area.
Embodiment 3
[0288] FIG. 16 is a configuration diagram of the wireless
positioning system of Embodiment 3.
[0289] The wireless positioning system according to Embodiment 3
includes mobile wireless terminals 300a to 300c in addition to the
wireless positioning system configured in Embodiments 1 and 2.
[0290] The positioning management terminal 100 according to
Embodiment 3 includes a similar configuration to the positioning
management terminal 100 according to Embodiments 1 and 2.
[0291] The terminal information storage section 150 of the
positioning management terminal 100 according to Embodiment 3
stores the terminal address 701, position information 702, and the
adjacent terminal list 703 regarding the mobile wireless terminal
300 as well in addition to information that the terminal
information storage section 150 in Embodiments 1 and 2 stores.
[0292] The positioning object decision section 130 of the
positioning management terminal 100 according to Embodiment 3
selects a positioning standard terminal for positioning the mobile
wireless terminal 300 from the adjacent terminal information
regarding the mobile wireless terminal 300 and position information
702 of the wireless terminal 200 in addition to the positioning
object decision section 130 in Embodiments 1 and 2.
[0293] The positioning procedure management section 120 of the
positioning management terminal 100 according to Embodiment 3
manages procedure for positioning the mobile wireless terminal 300
in addition to the positioning procedure management section 120 in
Embodiments 1. and 2.
[0294] Since the position calculation section 140 and the
communication section 110 of the positioning management terminal
100 in Embodiment 3 are the same as those of in Embodiments 1 and
2, descriptions will be omitted.
[0295] The configuration of the wireless terminal 200 according to
Embodiment 3 is the same as that of the wireless terminal 200
according to Embodiments 1 and 2. Each component of the wireless
terminal 200 is the same.
[0296] FIG. 17 is a function block diagram of a mobile wireless
terminal 300.
[0297] The mobile wireless terminal 300 has the same configuration
as the wireless terminal 200 according to Embodiment 3. Functions
of each component are the same as those explained in Embodiment
2.
[0298] As mentioned above, each configuration of the wireless
positioning system according to embodiment 3 is explained.
[0299] Next, descriptions will be given to operation thereof.
[0300] FIG. 18 is an entire operation sequence of the wireless
positioning system of Embodiment 3. In the following, each step in
FIG. 18 will be explained.
[0301] After the operation to obtain position information 702 of
all the wireless terminals 200 in Embodiments 1 and 2, an operation
for calculating the position of the mobile wireless terminal 300 is
further added to make the operations in Embodiment 3.
[0302] (S1800)
[0303] The positioning management terminal 100 performs positioning
of all the wireless terminals 200 by the method explained in
Embodiments 1 and 2. Next, the positioning management terminal 100
performs an operation to calculate the position of the mobile
wireless terminal 300 explained in the following.
[0304] (S1801)
[0305] The positioning procedure management section 120 of the
positioning management terminal 100 transmits the adjacent terminal
data request packet 1300 to the mobile wireless terminal 300 that
calculates a position via the communication section 110 to obtain
the adjacent terminal of the mobile wireless terminal 300. As for
how to obtain the adjacent terminal, method explained in Embodiment
2 is employed
[0306] (S1802)
[0307] The positioning object decision section 130 of the
positioning management terminal 100 selects (N+1) wireless
terminals 200 whose positions are defined as a positioning standard
terminal among the adjacent terminals of the mobile wireless
terminals 300 that the terminal information storage section 150
stores.
[0308] When selecting the positioning standard terminal, it may be
randomly selected among (N+1) or more wireless terminals 200 whose
positions are defined. A combination of the wireless terminals 200
having the highest evaluation may be selected using a suitable
evaluation function.
[0309] (S1803)
[0310] The positioning procedure management section 120 of the
positioning management terminal 100 generates a range-finding data
request packet 500 whose range-finding object terminal address 505
is the address of the positioning standard terminal selected by the
positioning object decision section 130 with the mobile wireless
terminal 300 being the terminal to be positioned.
[0311] Next, the positioning procedure management section 120
transmits the range-finding data request packet 500 to the mobile
wireless terminal information storage section 300 via the
communication section 110.
[0312] Upon receiving the range-finding data request packet 500,
the mobile wireless terminal 300 performs range-finding with the
wireless terminal 200 specified by the range-finding object
terminal address 505 to transmit the range-finding data response
packet 600 to the positioning management terminal 100.
[0313] (S1804)
[0314] When the positioning management terminal 100 receives the
range-finding data response packet 600, the position calculation
section 140 calculates the position of the mobile wireless terminal
300.
[0315] As for the positioning of the mobile wireless terminal 300,
the positioning management terminal 100 may perform positioning of
positioning of each mobile wireless terminal 300 on a regular
basis. Alternatively, from the mobile wireless terminal 300, a
signal (not shown) to require positioning of the self terminal is
transmitted to the positioning management terminal 100. Upon
receiving the signal, the positioning management terminal 100 may
perform positioning of the mobile wireless terminal 300.
[0316] Further, the user may command the positioning management
terminal 100 to perform positioning, and the positioning of the
mobile wireless terminal 300 may be performed according to the
command.
[0317] As mentioned above, in Embodiment 3, (N+1) or more wireless
terminals 200 are selected as positioning standard terminals among
the wireless terminals 200 automatically positioned by obtaining
the adjacent terminal. The distance between the positioning
standard terminal and the mobile wireless terminal 300 is measured
to position the mobile wireless terminal 300.
[0318] Thereby, the mobile wireless terminal 300 can be positioned
without installing a number of base stations over a wide area to
configure positions of the base stations.
[0319] Therefore, pre-configuration can be drastically reduced
necessary for, positioning the positioning standard terminal
300.
Embodiment 4
[0320] In the above-mentioned Embodiments 1 to 3, a procedure for
the position calculation section 140 to calculate the position of
the terminal to be positioned can be as follows.
[0321] (Position Calculation Method 1)
[0322] The position calculation section 140 obtains the
intersection of a circle whose radius is equal to position
information 705 between the terminal to be positioned and each
positioning standard terminal as the position of the terminal to be
positioned with the position of each positioning standard terminal
being the center.
[0323] (Position Calculation Method 2)
[0324] P.sub.i (i=1 . . . k) denotes the position of each
positioning standard terminal, P.sub.t denotes the position of the
terminal to be positioned, and d.sub.i (i=1 . . . k) denotes the
distance between each positioning standard terminal and the
terminal to be positioned.
[0325] The position calculation section 140 calculates the position
of the terminal to be positioned whose distance error becomes
minimum by calculating P.sub.t that makes a evaluation function
.epsilon. (P.sub.t) as follows minimum, for example, using
least-square method.
( p t ) = i = 1 k ( p i - p t - d k ) 2 [ Formula 1 ]
##EQU00001##
Embodiment 5
[0326] In Embodiment 5 of the present invention, descriptions will
be given to the method of evaluating measurement accuracy of the
terminal to be positioned. The configuration of the wireless
positioning system and each terminal is the same as Embodiments 1
to 4.
[0327] In Embodiment 5, when the terminal to be positioned has
(N+1) adjacent terminals whose positions are defined, the
positioning object decision section 130 of the positioning
management terminal 100 evaluates the combination of the wireless
terminals 200 to be a candidate for the positioning standard
terminal according to, for example, an evaluation function as
follows to select the combination of the wireless terminals 200
having the highest evaluation as the positioning standard
terminal.
[0328] (Evaluation Function 1): Determinant: 1
[0329] For example, among adjacent terminals for which (N+1) or
more position information 702 has been defined, regarding a
combination of the wireless terminals 200 to be the positioning
standard terminal, the position of the positioning standard
terminal is made to be {P.sub.0, P.sub.1, . . . , P.sub.N},
respectively.
[0330] Among them, the following determinant M is made to be an
evaluation function, whose element is a difference vector between
{P.sub.1, . . . , P.sub.N} and {P.sub.0}.
M=[p.sub.1 . . . p.sub.0, . . . , p.sub.N-p.sub.0] [Formula 2]
[0331] The positioning object decision section 130 calculates
values of the evaluation function regarding the combination of all
the wireless terminals 200 to be a candidate of the positioning
standard terminal to select the combination having the highest
value of the evaluation function as the positioning standard
terminal.
[0332] In general, when the positioning standard terminals of three
points are on the same straight line in the calculation of the
two-dimensional position, and when the positioning standard
terminals of four points are on the same plane in the calculation
of the three-dimensional position, a plurality of calculation
position candidates exist and measurement accuracy is
deteriorated.
[0333] The above evaluation function denotes a dispersion degree in
position relation of the positioning standard terminal.
[0334] Thus, by selecting the combination having a higher value of
the evaluation function, the positioning standard terminal having
more dispersed position relation enables measurement of the
position of the position of the positioning standard terminal,
resulting in improvement of measurement accuracy.
[0335] (Evaluation Function 2) Determinant: 2
[0336] Similarly, the same effect will be obtained by making the
following determinant M to be the evaluation function, whose
element is a normalized difference vector between {P.sub.1, . . . ,
P.sub.N} and {P.sub.0}.
M = [ p 1 - p 0 p 1 - p 0 , , p N - p 0 p N - p 0 ] [ Formula 3 ]
##EQU00002##
[0337] (Evaluation Function 3): Evaluation of Accuracy of
Calculated Position: 1
[0338] P.sub.i denotes the position of the wireless terminal 200
(suffix is made to be i) whose position information 702 is defined.
D.sub.ij denotes the distance information 705 with other wireless
terminal 200 (suffix is made to be j) whose position information
702 is defined. The positioning object decision section 130
calculates an evaluation value g.sub.i as follows.
g t = 1 N j N ( p t - p j - d ij ) 2 [ Formula 4 ] ##EQU00003##
[0339] N is the number of the adjacent terminal whose position
information 702 has been defined and distance information 705 has
been obtained among the adjacent terminals of the wireless terminal
i in the terminal information storage section 150 of the
positioning management terminal 100.
[0340] Next, among the adjacent terminals whose position
information 702 has been defined, the positioning object decision
section 130 selects (N+1) terminals having a smaller evaluation
value g.sub.i in order to select as the positioning standard
terminal.
[0341] The evaluation value g.sub.i denotes a degree of difference
between a distance calculated by the position relation calculated
by the position calculation section 140 and distance information
705 obtained from the distance measurement section 220. The smaller
the value g.sub.i, the more the position calculated by the position
calculation section 140 corresponds with the distance information
705 obtained by the measurement of the distance measurement section
220.
[0342] That is, the smaller the evaluation value g.sub.i, the
higher the position accuracy calculated by the position calculation
section 140.
[0343] Accordingly, by employing the combination of the positioning
standard terminal having the smallest evaluation value g.sub.i, the
terminal to be positioned can be positioned with the wireless
terminal 200 having a high calculation position accuracy being the
positioning standard terminal, resulting in improvement of
positioning accuracy of the terminal to be positioned.
[0344] (Evaluation Function 4): Evaluation of Accuracy of
Calculated Position: 2
[0345] A value denoting the accuracy of the calculated position as
follows may be used as the evaluation value g.sub.i, for
example.
g i = 1 N j N ( p i - p j - d ij d ij ) 2 OR g i = 1 N j N ( p i -
p j - d ij p i - p j ) 2 [ Formula 5 ] ##EQU00004##
[0346] In general, the distance information 705 measured by
wireless includes errors. The position information 702 calculated
by the distance information 705 including errors also includes
errors.
[0347] When calculating the position of the next wireless terminal
200 using the position information 702 including errors,
calculation position errors of the terminal to be positioned are
supposed to grow as the procedure advances.
[0348] Therefore, by selecting the positioning standard terminal
capable of improving positioning accuracy of the terminal to be
positioned like the above (evaluation function 3) and (evaluation
function 4) to calculate positions in order, a wireless positioning
system having a few position errors can be obtained.
[0349] In Embodiment 5, when there are a plurality of the wireless
terminals 200 in which (N+1) or more position information 702 of
the adjacent terminals is defined, the positioning object decision
section 130 may select the combination of the highest evaluation as
the terminal to be positioned and the positioning standard terminal
by evaluating combinations of the wireless terminals 200 that could
all be the positioning standard terminals of all the wireless
terminals 200 according to the above evaluation function.
[0350] Thus, the combination of the wireless terminals 200 having
the highest positioning accuracy of the terminal to be positioned
can be positioned as the positioning standard terminal, resulting
in the improvement of positioning accuracy of the entire wireless
positioning system.
Embodiment 6
[0351] In Embodiment 6 of the present invention, descriptions will
be given to a method in which position information 702 of the
wireless terminal 200 is calculated as relative coordinates in
place of absolute coordinates to be stored in the terminal
information storage section 150. Configurations of the wireless
positioning system and each terminal is the same as Embodiments 1
to 5.
[0352] FIG. 19 is a sequence diagram showing procedure in which
relative positions of the wireless terminal 200 of (N+1) or more
are obtained and stored in position information 702. Each step of
FIG. 19 will be explained as follows.
[0353] (S1901)
[0354] The positioning procedure management section 120 of the
positioning management terminal 100 selects k (k is an integer
greater than N+1) wireless terminals 200 (here, k=4 and suffixes
are a to d) to be adjacent terminals each other from information of
the adjacent terminal that terminal information storage section 150
stores.
[0355] The positioning procedure management section 120 transmits
the range-finding data request packet 500 including addresses of
the wireless terminals 200b to 200d as range-finding object
terminal addresses 505 to the wireless terminal 200a.
[0356] Upon receiving the range-finding data request packet 500,
the wireless terminal 200a performs range-finding among the
wireless terminals 200b to 200d to transmit the range-finding data
response packet 600 to the positioning management terminal 100.
[0357] (S1902) to (S1903)
[0358] The positioning management terminal 100 transmits the
range-finding data request packet 500 including addresses of the
wireless terminals 200b to 200d whose distances are undefined as
range-finding object terminal addresses 505 to the wireless
terminals 200b to 200d to obtain mutual distance information 705 of
the wireless terminals 200a to 200d.
[0359] (S1904)
[0360] The position calculation section 140 of the positioning
management terminal 100 calculates relative positions of the
wireless terminals 200a to 200d from obtained mutual distance
information 705.
[0361] For example, in the case where three-dimension positions of
the wireless terminals 200a to 200d are obtained, the position of
the wireless terminal 200a is made to be P.sub.1=(0, 0, 0), that of
the wireless terminal 200b P.sub.2=(x.sub.2, 0, 0), that of the
wireless terminal 200c P.sub.3=(x.sub.3, y.sub.3, 0), and the
positions except 200a to 200c among k wireless terminals 200 being
made to be P.sub.i=(x.sub.i, y.sub.i, z.sub.i) (i=4, . . . , k, x,
y, and z are unknown)
[0362] The position calculation section 140 can obtain relative
positions of each wireless terminal 200 with the position of p1
being an origin by obtaining a position that makes a difference
between a distance obtained from the calculated position and the
measured distance information 705 to be minimum.
[0363] Thus, by calculating the relative position to store it into
the position information 702, the wireless terminal 200 can be
obtained whose (N+1) or more position information 702 have been
confirmed prior to start of the position calculation operation.
[0364] Thereby, with no configuration of the positions of (N+1) or
more wireless terminals 200, the positions of all the wireless
terminals 200 can be obtained.
[0365] With the method above, relative position may possibly be
obtained which may be a mirror-symmetry or may be subjected
entirely to rotational transfer or parallel displacement against a
true position, however, a manual input by input means (not shown)
may be allowable to correct the mirror-symmetry and rotation to
perform correction.
[0366] Thereby, position information 702, in which mirror-symmetry
and rotated position are corrected, is obtained and the position
equivalent to the true position can be obtained.
[0367] The above mentioned relative position may be calculated from
mutual distance information 705 of the wireless terminal 200 by
determining only signs of unknown variables of the above-mentioned
P.sub.2=(x.sub.2, 0, 0) and P.sub.3=(x.sub.3, y.sub.3, 0) in
advance to install such that the position relation in the
predetermined k wireless terminals 200 should have predetermined
signs.
[0368] Thereby, the position equivalent to the true position can be
obtained with neither mirror-symmetry nor rotation of the whole by
the installation with only signs of the position relation being
matched with coordinates for calculating the position.
Embodiment 7
[0369] In Embodiment 7 of the present invention, descriptions will
be given to a method of recalculating the calculated position
information 702 after positioning to correct and improve accuracy.
The configuration of the wireless positioning system and each
terminal is the same as Embodiments 1 to 6.
[0370] (Recalculation Method 1)
[0371] The position calculation section 140 of the positioning
management terminal 100 refers again to the distance information
705 and the position information 702 that the terminal information
storage section 150 stores after the completion of the positioning
to recalculate the position of each wireless terminal 200.
[0372] When the position calculation section 140 recalculates
position information, since much more distance information 705 is
stored in the terminal information storage section 150 compared
with the above-mentioned step in the middle of the positioning
operation, positioning accuracy can be further improved using the
distance information 705.
[0373] (Recalculation Method 2)
[0374] After all the positioning procedures are completed and
positioning is concluded, the position calculation section 140 of
the positioning management terminal 100 transmits the range-finding
data request packet 500 regarding part of or all the distance
information 705 among undefined distance information 705 to correct
position information 702 upon increasing the number of data of
distance information 705.
[0375] Through this method, by increasing the number of data of
distance information 705, accuracy can be more precisely
improved.
[0376] Regarding the adjacent terminal whose distance information
705 is undefined, the above-mentioned evaluation value g.sub.i is
calculated and only distance information 705 of the adjacent
terminal whose evaluation value g.sub.i is smaller than a
predetermined threshold value (=position information is high) is
added, and the undefined distance information 705 is obtained.
[0377] By additionally obtaining distance information 705 of the
adjacent terminal having a smaller evaluation value g.sub.i and
calculating the position using distance information 705, distance
information 705 of the wireless terminal 200 whose position is more
precisely measured can be used, resulting in the improvement of
positioning accuracy of the wireless terminal 200.
[0378] (Recalculation Method 3)
[0379] Regarding the combination of (N+1) or more wireless
terminals 200, the position calculation section 140 of the
positioning management terminal 100 calculates the number of the
wireless terminals 200 to be an adjacent terminal in common from
each wireless terminals 200 included in the combination for each
combination after all the positioning procedures are completed and
positioning is concluded.
[0380] Next, the combination having the maximum number is selected
as the positioning standard terminal. The wireless terminal 200 for
which the combination becomes the adjacent terminal in common is
selected as the terminal to be positioned respectively. Then, the
position of each terminal to be positioned is calculated.
[0381] Thus, the position of the terminal to be positioned is
calculated based on the position information 702 of the common
positioning standard terminal, allowing to prevent the
above-mentioned problem of propagation of position errors.
Embodiment 8
[0382] The evaluation value g.sub.i showing calculation position
accuracy explained in Embodiment 5 may be output and presented to
other wireless terminals via wireless or wired interfaces as an
index of accuracy of position information 702. (not shown)
[0383] By presenting the index of accuracy of position information
702 along with position information 702, the system utilizing the
position information 702 obtained form the present wireless
positioning system becomes possible to use the position information
702 added with calculation position accuracy.
[0384] The evaluation value g.sub.i showing accuracy may be
displayed on the screen (not shown) operated by workers along with
position information 702. Specifically, it is conceivable that
display means such as a liquid crystal display and a light emitting
diode is provided on the positioning management terminal 100, for
example, and an accuracy index value is displayed thereon.
Embodiment 9
[0385] As explained in Embodiment 3, when the mobile wireless
terminal 300 exists in the wireless positioning system, the mobile
wireless terminal 300 may be actually fixedly installed in the
wireless positioning system instead of being mobile.
[0386] The fixed wireless terminal 200 additionally installed to
the wireless positioning system may be handled as the mobile
wireless terminal 300.
[0387] Even the wireless terminal 200 is additionally installed, by
calculating position as the mobile wireless terminal 300, the added
wireless terminal 200 searches the adjacent terminal and selects
the position standard terminal having higher position calculation
accuracy to perform range-finding only with the position standard
terminal.
[0388] Therefore, the position of the added wireless terminal 200
can be automatically obtained and communication amount for
range-finding can be reduced.
[0389] In Embodiment 3, the mobile wireless terminal 300 and the
wireless terminal 200 are configured as the different terminal,
however, they may be treated as the same wireless terminal 200.
[0390] In this case, a sign that discriminates whether the wireless
terminal 200 is the mobile wireless terminal 300 or not is stored
in the terminal information storage section 150 of the positioning
management terminal 100. The positioning procedure management
section 120 positions each wireless terminal 200 and mobile
wireless terminal 300 according to the sign.
[0391] The sign for the above discrimination may be switched during
the system operation.
[0392] For example, positioning may be performed under a initially
installed condition that all the terminals are the wireless
terminal 200. Thereafter part of the wireless terminal 200 is
switched for the mobile wireless terminal 300, and positioning may
be performed for the relevant mobile wireless terminal 300 as
needed according to the method explained in Embodiment 3.
[0393] Thus, a positioning method becomes possible in which
positioning is performed including, for example, the fixed and
immobile wireless terminal 200 and the mobile wireless terminal 300
that does not move at the time of positioning of each wireless
terminal 200 and moves thereafter, and then only the mobile
wireless terminal 300 is positioned in repetition.
[0394] Positioning of much more wireless terminals 200 increases
candidates of the available positioning standard terminal,
therefore, high precision positioning can be performed using more
accurate positioning standard terminal and by correcting by the
distance of the positioning standard terminal of higher position
calculation accuracy after the positioning.
[0395] In the case where after each wireless terminal 200 is once
installed, installation position of only part of the wireless
terminal 200 is moved, the position can be re-measured with smaller
communication amount by temporarily handling the wireless terminal
200 as the mobile wireless terminal 300.
Embodiment 10
[0396] In Embodiments 1 to 9 the above, the number of the
positioning standard terminal selected by the positioning object
decision section 130 is made to be (N+1), however, it is possible
to select more than (N+1) positioning standard terminals to
calculate the position of the terminal to be positioned from the
distance from more than (N+1) positioning standard terminals.
[0397] Position calculation by distance information 705 from much
more positioning standard terminals improves the positioning
accuracy of the terminal to be positioned.
[0398] The evaluation value g.sub.i showing the above-mentioned
position calculation accuracy may be utilized to select an
appropriate number of the positioning standard terminals among more
than (N+1) positioning standard terminals.
[0399] For example, the wireless terminal 200 whose evaluation
value g.sub.i is smaller than a predetermined threshold value may
be selected as the positioning standard terminal.
[0400] Thus, such a selection of the positioning standard terminal
enables selection of a number of wireless terminals 200 having high
position calculation accuracy alone as the positioning standard
terminal, resulting in improvement of positioning accuracy of the
terminal to be positioned.
Embodiment 11
[0401] In Embodiment 11 of the present invention, descriptions will
be given to an operation example where the number of the adjacent
terminals whose position known is poor and the number of
positioning standard terminals is scarce. The configuration of the
wireless positioning system and each terminal is the same as
Embodiments 1 to 10.
[0402] The positioning object decision section 130 reduces the
dimension to select N positioning standard terminals when the
number of the adjacent terminals is less than (N+1) for all the
position-undefined wireless terminals 200 and mobile wireless
terminals 300.
[0403] The positioning procedure management section 120 performs
range-finding of the positioning standard terminal and the terminal
to be positioned to calculate the position of the terminal to be
positioned in the (N-1)-th dimension space determined by the
positions of the N positioning standard terminals selected by the
positioning object decision section 130.
[0404] The calculation is allowable by reducing the dimension from
(N-1). The position may be calculated using restriction information
such that the terminal is installed on the floor face or the
ceiling face, for example.
[0405] Thus, in the case where the number of the adjacent terminals
is less than (N+1), the position of the wireless terminals 200 and
the mobile wireless terminals 300 can be defined in the part where
the wireless terminals 200 are sparsely arranged by calculating the
position with a reduced dimension.
Embodiment 12
[0406] In the above-mentioned Embodiments 1 to 11, the position is
adapted to be calculated by distance information of the
position-known wireless terminal 200. However, besides the
distance, by measuring the time difference of arrival of the radio
waves transmitted from the terminal to be positioned at each
positioning standard terminal, it is possible to calculate the
position of the terminal to be positioned as an intersection point
of the hyperbolic line with the position of each positioning
standard terminal and measured radio wave propagation time
difference being parameters.
[0407] Evidently, the same effect can be obtained by deciding the
positioning standard terminal and the terminal to be positioned by
the present invention in succession regardless of a positioning
method to calculate the position of the terminal to be
positioned.
Embodiment 13
[0408] In the above-mentioned Embodiments 1 to 12, the positioning
management terminal 100 may include the distance measurement
section 220 and the range-finding data processing section 230, and
the above-mentioned positioning procedure may be followed with the
positioning management terminal 100 itself being subjected to
positioning.
[0409] Similarly, the positioning management terminal 100 may
further include the adjacent terminal search section 240 and the
adjacent terminal data processing section 250 and to perform
positioning as the wireless terminal 200 or the mobile wireless
terminal 300 explained in Embodiments 2 and 3.
[0410] Thereby, automated position calculation becomes possible
including the positioning management terminal 100.
Embodiment 14
[0411] In the above-mentioned Embodiments 1 to 13, distance
measurement section 220 calculates the distance between the
wireless terminals 200 based on the radio wave propagation delay
time, however, other distance measurement methods such as radio
wave reception strength may be utilized.
Embodiment 15
[0412] FIG. 20 is a configuration diagram of an environment
measurement system of Embodiment 15.
[0413] The environment measurement system according to Embodiment
15 is a system that measures environmental conditions of a
measurement object space, including a fixed sensor terminal 2100
and a mobile sensor terminal 2200.
[0414] The fixed sensor terminals 2100 as fixedly installed in the
measurement object space in plural to measure environmental
conditions neighboring the self-terminal.
[0415] The mobile sensor terminal 2200 measures environmental
conditions neighboring the self-terminal while moving in the
measurement object space. Measurement points whose environmental
conditions the mobile sensor terminal 2200 measures are supposed to
be preconfigured.
[0416] FIG. 21 is a functional block diagram of a fixed sensor
terminal 101.
[0417] The fixed sensor terminal 2100 includes a terminal control
section 2110, a wireless communication section 2111, and an
environment measurement section 2112.
[0418] The terminal control section 2110 obtains measurement values
of environmental conditions measured by the environment measurement
section 2112 and exchanges data with other sensor terminals via the
wireless communication section 2111.
[0419] The wireless communication section 2111 performs wireless
communication with other sensor terminals.
[0420] The environment measurement section 2112 includes one or a
plurality of sensors such as a temperature sensor, a humidity
sensor, and an illuminance sensor to measure environmental
conditions neighboring the self-terminal such as temperature,
humidity, and illuminance.
[0421] Kinds of sensors are not limited to the temperature sensor,
the humidity sensor, and the illuminance sensor but an arbitrary
sensor can be used according to the environment conditions in need
of measurement. For example, a sensor may be used that detects a
particular chemical substance.
[0422] FIG. 22 is a functional block diagram of a mobile sensor
terminal 2200.
[0423] The mobile sensor terminal 2200 includes a terminal control
section 2210, a wireless communication section 2211, an environment
measurement section 2212, a wireless positioning section 2213, a
self position control section 2214, and a drive section 2215.
[0424] The terminal control section 2210 obtains measurement values
measured by the environment measurement section 2212, and exchanges
data with other sensor terminals through the wireless communication
section 2211.
[0425] The terminal control section 2210 has a role to control the
position of the self-terminal, in addition. For example, the
terminal control section 2210 makes the mobile sensor terminal 2200
move to a desired position by the function of the self position
control section 2214, or detects to manage the position of the
mobile sensor terminal 2200 by the function of the wireless
positioning section 2213.
[0426] The wireless communication section 2211 performs wireless
communication with other sensor terminals.
[0427] The configuration and functions of the environment
measurement section 2212 are the same as those of the environment
measurement section 2112.
[0428] The wireless positioning section 2113 detects the position
of the mobile sensor terminal 2200 using wireless communication.
Method of detection will be mentioned later.
[0429] The self position control section 2214 controls the position
of the mobile sensor terminal 2200 to be a desired position by
properly operating the drive section 2215 from a target position
and the current position of the mobile sensor terminal 2200.
[0430] As for a method of controlling the sensor terminal to be the
desired position, such a method is conceivable that to calculate a
deviation between the target position and the current position of
the mobile sensor terminal 2200 to change operation time of the
drive section 2215 based on the deviation, and to give an output
command in proportion to the deviation to the drive section
2215.
[0431] The drive section 2215 is means to move the mobile sensor
terminal 2200. The drive section 2215 includes a motor and wheels,
for example, being capable of moving the mobile sensor terminal
2200 by rotating wheels. The drive section 2215 may be configured
so that a walk form by a caterpillar and link mechanism move the
mobile sensor terminal 2200 as well.
[0432] The terminal control section 2110, the terminal control
section 2210, the wireless positioning section 2213, and the self
position control section 2214 may be configured using hardware such
as a circuit device that achieves these functions or may be
configured using operation devices such as a microprocessor and a
CPU (Central Processing Unit) and software specifying their
operations.
[0433] The wireless communication section 2111 and the wireless
communication section 2211 appropriately include a necessary
configuration such as a wireless communication interface.
[0434] In the above, the configuration of the environment
measurement system according to Embodiment 15 is explained.
[0435] Next, descriptions will be given to a position detection
method by the wireless positioning section 2213.
[0436] FIG. 23 is a diagram illustrating procedure for a wireless
positioning section 2213 to calculate the distance between the
mobile sensor terminal 2200 and a fixed sensor terminal 2100. Each
step of FIG. 23 will be explained as follows.
[0437] (S401)
[0438] The mobile sensor terminal 2200 transmits a range-finding
request signal via the wireless communication section 2211.
[0439] (S402)
[0440] Upon receiving the range-finding request signal, the fixed
sensor terminal 2100 transmits a range-finding response signal to
the mobile sensor terminal 2200.
[0441] (S403)
[0442] The mobile sensor terminal 2200 receives the range-finding
response signal via the wireless communication section 2211. The
wireless positioning section 2213 measures the response time from
the transmission of the range-finding request signal to the
reception of the range-finding response signal.
[0443] The wireless positioning section 2213 can measure the
response time by such a method as to start time measurement by a
counter at the time of transmitting the range-finding request
signal and to read a time measurement value by the counter at the
time of receiving the range-finding response.
[0444] (S404)
[0445] The wireless positioning section 2213 of the mobile sensor
terminal 2200 calculates the distance between the mobile sensor
terminal 2200 and the fixed sensor terminal 2100 by multiplying the
response time measured in step S403 by the velocity of the
electromagnetic wave and by referring to a correspondence table
between a predetermined response time and the distance.
[0446] FIG. 24 is a diagram illustrating a method for the wireless
positioning section 2213 to calculate the position of the mobile
sensor terminal 2200.
[0447] The wireless positioning section 2213 performs procedure to
calculate the distance between the mobile sensor terminal 2200 and
the fixed sensor terminal 2100 for a plurality of fixed sensor
terminals 2100 (for example, 100a to 100c in FIG. 24).
[0448] Next, the wireless positioning section 2213 obtains a circle
whose center is the fixed sensor terminal 2100 and whose radius is
calculated distance between terminals from the inter-terminal
distances between a plurality of fixed sensor terminals 2100 and
the mobile sensor terminal 2200 and positions of each fixed sensor
terminals 2100 (assumed to be known).
[0449] The wireless positioning section 2213 can detect the area
where these circles intersect as the position of the mobile sensor
terminal 2200.
[0450] Therefore, in order to detect the position of the mobile
sensor terminal 2200 with high precision, it is preferable to
calculate the inter-terminal distance among three or more fixed
sensor terminals 2100.
[0451] In the above, a method of detecting the position, of the
mobile sensor terminal 2200 is explained.
[0452] Next, descriptions will be given to operation of the mobile
sensor terminal 2200 to measure environmental conditions.
[0453] FIG. 25 is an operation flow when the mobile sensor terminal
2200 measures environmental conditions.
[0454] Each step of FIG. 25 will be explained as follows.
[0455] (S601)
[0456] The terminal control section 2210 decides a measurement
point where the environmental conditions are measured next in the
preset measurement point list. The terminal control section 2210
may select the measurement point according to a preset order, or
select the nearest measurement point from the current position of
the mobile sensor terminal 2200. The next measurement point may be
selected by other methods.
[0457] (S602)
[0458] The wireless positioning section 2213 detects the position
of the mobile sensor terminal 2200 by the methods explained in
FIGS. 23 and 24.
[0459] (S603)
[0460] The self position control section 2214 performs control
operation to move the mobile sensor terminal 2200 to a specified
measurement point with the measurement point decided in step S601
being a target position and with the position detected in step S602
being the current position.
[0461] The self position control section 2214 decides operation
time of the drive section 2215 from the deviation between the
target position and the current position, for example, to move the
mobile sensor terminal 2200 to the measurement point by making the
drive section 2215 operate for the operation time.
[0462] Alternatively, the self position control section 2214 may
move the mobile sensor terminal 2200 to the measurement point by
detecting and moving the current position by the wireless
positioning section 2213 in repetition until the deviation between
the position of the measurement point and the current point becomes
a predetermined threshold or less.
[0463] As for the method of controlling the position of the mobile
sensor terminal 2200, a method of controlling a general
self-propelled robot may be applied.
[0464] (S604)
[0465] When the mobile sensor terminal 2200 moves to the
measurement point, the environment measurement section 2212
measures environmental conditions neighboring the
self-terminal.
[0466] (S605)
[0467] The terminal control section 2210 judges whether measurement
of environmental conditions is completed or not for all measurement
points included in the measurement point list. When there is an
uncompleted measurement point, return to step S601 to repeat the
same processing. After the completion of the measurement in all the
measurement points included in the measurement point list, the
measurement of environmental conditions is completed.
[0468] In the above, an operation of measuring environmental
conditions of the mobile sensor terminal 2200 is explained.
[0469] The fixed sensor terminal 2100 may measure environmental
conditions neighboring the self-terminal in synchronization with
the mobile sensor terminal 2200, or measure environmental
conditions independent of the mobile sensor terminal 2200.
[0470] As mentioned above, according to Embodiment 15, since small
number of the fixed sensor terminals 2100 and mobile sensor
terminals 2200 are adapted to measure environmental conditions of
the measurement object space, it is possible to measure
environmental conditions at many measurement points without
increasing sensors to be fixedly installed.
[0471] According to Embodiment 15, the wireless positioning section
2213 detects the current position of the mobile sensor terminal
2200 utilizing the wireless communication signal between the fixed
sensor terminal 2100 and the mobile sensor terminal 2200. The
mobile sensor terminal 2200 measures environmental conditions
utilizing the detection results to understand the position of the
self-terminal.
[0472] Thereby, with no need of installing other devices to be a
reference of the current position of the mobile sensor terminal
2200 such as a guide rail and a marker, an environment measurement
system can be introduced with less cost with ease.
[0473] In general, the position after a self-propelled robot moved
has an error against a target position.
[0474] In Embodiment 15, since the position of the mobile sensor
terminal 2200 is detected by wireless, an actually measured point
can be correctly grasped by holding both the measured environment
conditions and the detection point of the mobile sensor terminal
2200 even when errors exist from the measurement point.
[0475] That is, measurement of environment conditions at a position
other than a predetermined measurement point results in a correct
measurement of environment conditions of the measurement object
area because the correspondence relation itself is not erroneous
between the position and the environment conditions.
[0476] By performing feedback of the detected position to make it
move to the measurement point, the mobile sensor terminal 2200 can
be correctly moved to the measurement point.
Embodiment 16
[0477] FIG. 26 is a configuration diagram of an environment
measurement system of Embodiment 16.
[0478] In Embodiment 16, the fixed sensor terminal 2100 is
installed at a position where measurement of environmental
conditions is required for a larger time period than other
measurement points. The mobile sensor terminal 2200 measures
environmental conditions at the measurement position where no
larger time period is required other than that.
[0479] For example, in an environment measurement system that
measures the temperature inside a building, heat movement near a
window 2701 and a gateway 2702 is large, requiring measurement of
environmental conditions with a large time period. To the contrary,
in the floor portion other than that, no measurement with a large
time period is required.
[0480] Accordingly, as shown in FIG. 26, the fixed sensor terminal
2100 is installed at a position neighboring the window 2701 or near
the gateway 2702 where a large time period is required. The mobile
sensor terminal 2200 measures environmental conditions while moving
at measurement points besides those.
[0481] Even when the fixed sensor terminal 2100 and the mobile
sensor terminal 2200 measure environmental conditions in
synchronization, while the fixed sensor terminal 2100 continuously
measures environmental conditions of the same place, the mobile
sensor terminal 2200 measures environmental conditions of a
plurality of measurement points while moving.
[0482] As a result, the fixed sensor terminal 2100 more frequently
performs measurement of the same measurement point.
[0483] As mentioned above, in Embodiment 16, the fixed sensor
terminal 2100 is installed at a position where measurement is
required for a larger time period than other measurement points.
The mobile sensor terminal 2200 measures environmental conditions
at a position where no larger time period is required.
[0484] Thus, the fixed sensor terminal needs not to be installed at
all positions, enabling an effective measurement of environmental
conditions with fewer number of terminals. Further, a flexible
system can be configured according to demands of the system.
Embodiment 17
[0485] FIG. 27 is a configuration diagram of an environment
measurement system of Embodiment 17.
[0486] The environmental measurement system according to Embodiment
17 includes four or more mobile sensor terminals 2200. The
configuration of the mobile sensor terminal 2200 is the same as
Embodiments 15 and 16.
[0487] FIG. 28 is a diagram illustrating a state in which the
mobile sensor terminal 2200 switches a role of a self terminal.
[0488] In Embodiment 17, the mobile sensor terminals 2200 detect
the position each other to measure environmental conditions while
switching two roles: a role to be an object for moving and position
detection to move to the measurement point and the role to
designate a standard position for position detection without
moving.
[0489] Hereinafter, the mobile sensor terminal 2200 to play the
former role is referred to as a position detection object terminal
2902, and the mobile sensor terminal 2200 to play the latter role
is referred to as a position detection standard terminal 2901. The
measurement point list for measuring environmental conditions and
the initial position of each mobile sensor terminal 2200 is assumed
to be set in advance.
[0490] FIG. 29 is an operation flow for the position detection
object terminal 2902 to measure environmental conditions.
[0491] Descriptions will be given to each step in FIG. 29.
[0492] (S1001)
[0493] The present step is the same as the step S601 in FIG.
25.
[0494] (S1002)
[0495] The terminal control section 2210 decides the position
detection object terminal 2902 and position detection standard
terminal 2901 other than the same among each mobile sensor terminal
2200 based on the position of the measurement point decided in step
S1001. Hereinafter the position detection object terminal 2902
measures environmental conditions of the measurement point decided
in step S1001.
[0496] The terminal control section 2210 makes the farthest mobile
sensor terminal 2200 from the measurement point decided in step
S1001 the position detection object terminal 2902, for example, and
makes other mobile sensor terminals 2902 the position detection
standard terminals 2901.
[0497] (S1003)
[0498] The wireless positioning section 2213 detects the position
of the position detection object terminal 2902. Position detection
can be performed by transmitting and receiving a range-finding
signal between the position detection object terminal 2902 and the
position detection standard terminal 2901 like the position
detection by the wireless positioning section 2213 in Embodiments
15 and 16.
[0499] (S1004)
[0500] The position detection object terminal 2902 moves to the
measurement point that the self position control section 2214
designates according to the same procedure as step S603 in FIG.
25.
[0501] (S1005)
[0502] The same as step S604 in FIG. 25.
[0503] (S1006)
[0504] The same as step S605 in FIG. 25.
[0505] As mentioned above, the environment measurement system
according to Embodiment 17 includes four or more mobile sensor
terminals 2200. The mobile sensor terminals 2200 measure
environmental conditions of the measurement object space by
detecting the position each other to move while switching two roles
of the position detection object terminal 2902 and the position
detection standard terminal 2901.
[0506] Thereby, with fewer terminals, environmental conditions at a
number of measurement points can be measured.
[0507] According to the environment measurement system according to
Embodiment 17, only by setting the initial mobile sensor terminal
2200, environmental conditions of the building and the factory can
be measured including position information. Thus, setting work for
starting environmental measurement can be drastically reduced.
[0508] The environment measurement system according to Embodiment
17 is constituted only by the more mobile sensor terminals 2200.
However, the position of the position detection object terminal
2902 may be detected by making a configuration including one or two
fixed sensor terminals 2100 to transmit and receive a range-finding
signal between the position detection object terminal 2902 and the
fixed sensor terminal 2100.
[0509] Thereby, position detection precision of the position
detection object terminal 2902 can be improved.
[0510] It is explained that in Embodiment 17, there are four or
more mobile sensor terminals 2200. However, if coarse precision is
allowable for position detection of the mobile sensor terminal
2200, the same method can be used as that explained in Embodiment
17 even when the mobile sensor terminal 2200 is three or less.
Embodiment 18
[0511] In Embodiment 18, an example will be explained in which a
decision method of the measurement point is changed in step S1001
of Embodiment 17. In Embodiment 18, such operations are performed
as follows in step S1001.
[0512] (S1001)
[0513] The terminal control section 2210 calculates a distance
between a position of the measurement point where measurement of
environmental conditions has not been completed among the preset
measurement point list and a current position of each mobile sensor
terminal 2200.
[0514] Next, the terminal control section 2210 makes a measurement
point in which at least three or more distances out of calculated
distances are smaller than a predetermined value to be the
following measurement point. The predetermined value is a
communicable distance of the wireless communication section 2211,
for example.
[0515] A decision of the next measurement point can prevent such an
event that the position detection object terminal 2902 moves beyond
a communicable distance with the position detection standard
terminal 2901 to cause a failure in position detection.
[0516] When there is a plurality of measurement points that
satisfies the above condition, a gravity center position of the
current position of each mobile sensor terminal 2200 is calculated.
Then, the next measurement point may be decided as the nearest
measurement point to the gravity center point among a plurality of
measurement points that satisfies the above condition.
[0517] Thereby, environmental conditions can be measured from the
point near the mobile sensor terminal 2200, making it possible to
reduce the time for measuring a moving distance and environmental
conditions.
Embodiment 19
[0518] In Embodiment 19, an example will be explained in which a
method of deciding the position detection object terminal 2902 and
the position detection standard terminal 2901 is changed in step
S1002 of Embodiment 17. In Embodiment 19, such operations are
performed as follows in step S1002.
[0519] (S1002: 1)
[0520] The terminal control section 2210 calculates a distance
between a position of the measurement point where measurement of
environmental conditions has not been completed among the preset
measurement point list and a current position of each mobile sensor
terminal 2200.
[0521] Next, the terminal control section 2210 selects three or
more mobile sensor terminals 2200 whose calculated distance is
smaller than a predetermined value to make these the position
detection standard terminal 2901. Other mobile sensor terminals
2200 are made to be position detection object terminals 2902.
[0522] (S1002: 2)
[0523] When there is a plurality of candidates of combination of
the position detection standard terminals 2901, the terminal
control section 2210 may make a combination having a high position
detection precision in a geometric relation with each measurement
point to be the position detection standard terminal 2901, and
other mobile sensor terminals 2200 to be the position detection
object terminals 2902.
[0524] For an evaluation index of selecting a combination having
high position detection precision, GIDOP (Geometric Dilution of
Precision) can be utilized that is used in the field of GPS (Global
Positioning System).
[0525] Thereby, position detection precision of the position
detection object terminal 2902 improves, achieving reduction in
position errors regarding the measurement point where environmental
conditions are measured.
[0526] An evaluation function may be defined by combining a method
of deciding the measurement point described in Embodiment 18 and
the method of deciding the position detection object terminal 2902
and the position detection standard terminal 2901 in Embodiment
19.
[0527] The terminal control section 2210 selects a measurement
point having the highest evaluation value of the evaluation
function, the position detection object terminal 2902, and the
position detection standard terminal 2901.
[0528] In this case, it is possible to integrally evaluate the
position of the measurement point and the combination of the
position detection object terminal 2902 and the position detection
standard terminal 2901 to improve the position detection precision,
as well.
Embodiment 20
[0529] In Embodiments 15 to 19 in the above, a measurement point
list for measuring environmental conditions is assumed to be
preset. In Embodiment 20, an operation example will be explained in
which the measurement point list is automatically generated.
[0530] Embodiment 20 is constituted by the fixed sensor terminal
2100 and the mobile sensor terminal 2200 like Embodiments 15 to 19.
Configuration of each terminal is the same as that of Embodiments
15 to 19.
[0531] FIG. 30 is a diagram showing the state in which a
measurement object space is divided.
[0532] In Embodiment 20, the measurement object space is divided
into a lattice shape of a predetermined interval. The measurement
point list is constituted by typical points 3101 of the area (cell)
sectioned by each lattice. The typical point 3101 is the center of
each cell for example.
[0533] By making the typical point 3101 of each cell to be the
measurement point, there is no need to configure the measurement
point list separately, making the preset work for starting
measurement of environmental conditions to be simpler.
[0534] Among cells partitioned in a lattice shape, the typical
point 3101 of the cell excluding the cell where the fixed sensor
terminal 2100 is installed may be the measurement point. Thereby,
an overlapping of the measurement point can be prevented, enabling
an efficient measurement of environmental conditions.
[0535] In the step for deciding the next measurement point (step
S601 or S1001) in Embodiments 15 to 19, a predetermined interval
between measurement points may be defined instead of selecting the
next measurement point from a preset measurement point list.
[0536] In that case, the terminal control section 2210 calculates
the position that is displaced by a predetermined interval from the
measurement point measured in the previous step.
[0537] Thus, the same effect as Embodiment 20 is exhibited by
sequentially calculating the next measurement point instead of
presetting the measurement point list.
[0538] In the step (S601 or S1001) for deciding the next
measurement point in Embodiments 15 to 19, the next measurement
point may be defined by deciding a random movement direction and
movement amount by pseudorandom numbers generation and the like to
follow the movement direction and movement amount.
[0539] In this case, by a random measurement while detecting the
position of the mobile sensor terminal 2200 by mobile
communication, it is possible to autonomously minutely measure the
entire measurement object space in place of pre-configuring the
measurement point list.
Embodiment 21
[0540] In Embodiment 21, a configuration example of the mobile
sensor terminal 2200 will be explained. Other configurations are
the same as Embodiments 15 to 20.
[0541] FIG. 31 is a configuration diagram of the mobile sensor
terminal 2200 of Embodiment 21.
[0542] The mobile sensor terminal 2200 according to Embodiment 21
includes a mobile cart 3201, a control module 3202, a support table
3203, and a sensor module 3204.
[0543] The mobile cart 3201 includes means for moving on a
two-dimension plane, for example, a wheel.
[0544] The terminal, control section 2210 and the wireless
communication section 2211 are built-in in the control module
3202.
[0545] The support table 3203 is a bar-shaped pedestal vertically
installed to the mobile cart 3201.
[0546] The sensor module 3204 accommodates the environment
measurement section 2212 and one or a plurality of the same is
installed along the support table 3203.
[0547] By configuring the mobile sensor terminal 2200 like the
above, it becomes possible to measure environmental conditions in
the height direction simultaneously, allowing more detailed
measurement of environmental conditions.
[0548] In the same way, as for the fixed sensor terminal 2100, a
bar-shaped support table may be provided and a plurality of sensor
modules may be installed on the support table. Thereby, more
detailed measurement of environmental conditions becomes possible
for the installation location of the fixed sensor terminal
2100.
Embodiment 22
[0549] FIG. 32 is a configuration diagram of a facility management
system of Embodiment 22.
[0550] The facility management system according to Embodiment 22
includes a facility management apparatus 3300 in addition to the
environment measurement system according to Embodiments 15 to
21.
[0551] The facility management apparatus 3300 includes a facility
management section 3301 and a wireless communication section
3302.
[0552] In Embodiment 22, the facility management apparatus 3300
obtains measurement data measured by the environment measurement
system through the wireless communication section 3302. The
facility management section 3301 controls facility equipment such
as air-conditioning and lighting based on the measurement data.
[0553] As mentioned above, according to Embodiment 22, fewer sensor
terminals measure a lot of environmental conditions, allowing
control of facility equipment based on measurement results.
[0554] Thereby, facility equipment can be controlled more minutely
such that temperature and lighting are adjusted to suite personal
tastes and facility equipment is controlled with high energy-saving
effect according to a fine temperature distribution in the
space.
Embodiment 23
[0555] In the above Embodiments 15 to 22, the fixed sensor terminal
2100 and the mobile sensor terminal 2200 can use an ultra wideband
impulse wireless signal that transmits an impulse signal at the
time of transmitting the range-finding request signal and the
range-finding response signal.
[0556] Thereby, the response time can be accurately measured,
allowing to detect an inter-terminal distance and a terminal
position more accurately.
[0557] In the above Embodiments 15 to 22, the inter-terminal
distance and the terminal position may be calculated based on a
received radio wave intensity of the wireless communication between
the mobile sensor terminal 2200 and the fixed sensor terminal
2100.
[0558] Alternatively, in the above Embodiments 15 to 22, the
inter-terminal distance and the terminal position may be detected
utilizing a time difference of reception of the transmitted
range-finding request signal from the mobile sensor terminal 2200
by each of a plurality of the fixed sensor terminals 2100, that is,
a radio wave transmission time difference.
[0559] In the above Embodiments 15 to 22, the position of the fixed
sensor terminals 2100 is supposed to be preconfigured, however, the
relative position of the fixed sensor terminals 2100 may be
calculated. For example, procedures as follows may be used.
[0560] Firstly, the distance between the fixed sensor terminals
2100 is calculated based on wireless communication with the same
method as the above. The position of the fixed sensor terminals
2100 is detected by obtaining the relative position between the
fixed sensor terminals 2100. Based on the position, the position of
the mobile sensor terminal 2200 can be detected.
[0561] In the above Embodiments 15 to 22, the position of the
mobile sensor terminal 2200 can be detected by installing a
plurality of the mobile sensor terminals 2200 to utilize the
range-finding signal between each mobile sensor terminal 2200 and
the fixed sensor terminals 2100 as well.
Embodiment 24
[0562] In the above Embodiments 15 to 23, it is configured that the
wireless positioning section 2213 is included in the mobile sensor
terminal 2200 to detect the position thereof, however, the present
invention is not limited to the above configuration.
[0563] For example, in place of the mobile sensor terminal 2200,
any of the fixed sensor terminals 2100 can include the wireless
positioning section 2213.
[0564] In this case, information such as a received radio wave
intensity, a radio wave propagation time, and a radio wave
propagation time difference is transmitted from the mobile sensor
terminal 2200 to the fixed sensor terminal 2100. The wireless
positioning section 2213 of the fixed sensor terminal 2100 detects
the position of the mobile sensor terminal 2200 based on the
information.
[0565] Alternatively, in the above Embodiments 15 to 23, the fixed
sensor terminal 2100 may measure the received radio wave intensity,
the radio wave propagation time, and the radio wave propagation
time difference by the wireless communication with the mobile
sensor terminal 2200.
[0566] The fixed sensor terminal 2100 transmits the measurement
values to other terminals having the wireless positioning section
2213. The wireless positioning section 2213 of the terminal that
received the information detects the position of the mobile sensor
terminal 2200.
[0567] In the above Embodiments 15 to 23, a central management
apparatus (not shown) and the like having a wireless communication
section may include the same function apart from the fixed sensor
terminal 2100 and the mobile sensor terminal 2200, for example.
[0568] In this case, the central management apparatus and the like
may be adapted to detect the position of the mobile sensor terminal
2200 or to transmit the measurement point whose environmental
conditions to be measured next to the mobile terminal 2200.
* * * * *